Case study: Hybrid & electric training pays off

By Edward Grigg, Swanley Garage Services

We received a call from a customer who lived some 40 miles away in a neighbouring county. They had a problem with their interior heater, it was not blowing out hot air into the cabin. The vehicle was a Mitsubishi Outlander Hybrid 2016 – they had contacted the main dealer and was told they would need to replace the entire cooling system at a cost of nearly £7,000!

The owner then went in search of an independent garage but were unable to find any in their local area willing to diagnose a fault on an electric/hybrid car. They came across us on the HEVRA network website and gave us a call. We’d had dealings with similar faults in the past so were more than happy to take a look for them. Being part of the HEVRA network, as well as just having completed Level 4 Hybrid and electric vehicle repair with James Dillon, gave us the confidence to know we would be able to resolve the issue for them.

The customer dropped the car over the next day and we went about our usual diagnostic routine. We carried out a full scan of the vehicle but unfortunately this returned no clues. We let the car warm up to confirm the customer complaint and sure enough, the heaters did not get hot. We did some off-vehicle research using technical information to learn about the system and how it works. This is not your average cooling system – it has a conventional cooling system similar to most cars, but it also has an auxiliary cooling system, which includes an electric water heater and electronic water pump. Being a Hybrid, it uses the electric heater and pump to keep the cabin air temperature hot when the vehicle is driving in electric mode.

A 4-way valve located on top of the gearbox

We used a thermal imaging camera to test the temperature of the various components and hoses of the cooling system and found a faulty 4-way valve located on top of the gearbox, close to the bulkhead. I spoke to Pete Melville at HEVRA and he recommended that we flush the system and replace a small filter located inside one of the heater matrix pipes at the same time as replacing the valve. He was also able to offer first-hand experience of how to bleed the cooling system after the repairs had been made.

A small filter located inside one of the heater matrix pipes

We carried out the repairs and bled through the system as per Pete’s recommendation. We also carried out an extended road test to confirm the repair was successful. It just goes to show that now is the time to make preparations to become sufficient in electric/hybrid vehicle repair as there are still not many people willing to take the jobs on and they can be quite profitable if carried out correctly.

A thermal imaging camera was used to test the temperature of the various components and hoses of the cooling system

New car focus: Lexus UX 250H

Tech-innovator Lexus, advances hybrid expectations in latest UX model – by Iain Robertson.

Last issue, we dug into the engineering simplicity of the brand- new Suzuki Jimny. As a complete antithesis to it, the luxury/ technological arm of Toyota, Lexus, is a premium quality brand to which ‘continuous advancement’ are its watchwords and Iain Robertson makes a six-point review of its latest but less ‘scary’ new 4×4 model, due to hit UK roads from March 2019. 

The compact Motor/Generators (MG1 and MG2) are located at the rear of the engine within the transaxle.

The company’s all-new UX 250h crossover is the result of a five-year development programme that involved hundreds of its engineers and technicians in the creation of one of the most advanced vehicles that even Lexus has ever built. This includes delivering a new, fourth generation, hybrid powertrain, each element of which benefits from a series of innovations and improvements in both design and overall efficiency. While you may not see a UX for several years in your workshops, Toyota/ Lexus told Autotechnician that it has improved accessibility to all normal service items, as a measure to cut maintenance costs and make it easier for non-franchise repairers. 


Running on 0W16 lubricant, the 2.0-litre in-line four-cylinder Atkinson-cycle engine is now one of the most efficient that Lexus has ever produced, achieving 41% thermal efficiency (put into perspective, the average petrol engine is around 22%, diesel around 30%, although the latest Toyota Prius hybrid unit is very close at 40%). Its advanced features include enlarged intake valve seats, cut by laser for greater precision, and a D4-S fuel injection system, which combines both direct and secondary port injectors per cylinder; the object being to speed-up airflow and create the most-efficient burn. A high (for an Atkinson-cycle non-turbo petrol engine) 14:1 compression ratio supports the overall efficiency target, while a simpler exhaust heat recirculation system provides speedier warm-up of the engine (120s at 10 degreesC) that also carries reduced emissions benefits. The unit is equipped with electric intelligent variable valve-timing (VVT-iE), retaining hydraulic operation of the exhaust valves and a faster-reacting electric system on the inlet side, which Lexus calculates will enhance driveability and reduce emissions, in all traffic conditions, loads and locations. 


A new front hybrid transaxle connects the engine to two electric Motor/Generators (MG1 for engine starting and battery charging functions, with MG2 driving the front wheels). To make it even more compact and to improve driving performance, a multi-axial layout includes an additional electric motor on the rear transaxle. The gearbox’s length has been reduced by about 45mm, which gives the steering gear more space to create a tighter turning circle (10.4m kerb-to-kerb). With overall transmission losses reduced by a quarter, the more efficient Motor/Generators yield better performance overall. 


The new Power Control Unit, PCU, is 20% more powerful but 10% lighter than previous versions fitted to both Lexus ES saloon and other Toyota models. Its size and weight were reduced by developing a new, compact circuit board, DC-DC converter and power stack structure. Combined, these items have reduced power losses over Toyota’s 1.8-litre hybrid unit by around 20% and improved the fuel economy, which is not merely essential for the changing governmental pressures placed on new cars but also for end users’ satisfaction, many of which will be from the heavily-taxed company car sector. 

The PCU is mounted directly above the front hybrid transaxle, as a result of its compact dimensions, having been moved from inside the cabin. An additional benefit is the lower, more aerodynamically efficient bonnet-line that offers better protection for pedestrians in the event of a collision. 


The compact Nickel Metal-hydride battery pack.

The UX 250h’s revised and more compact nickel-metal hydride (NiMH) battery helps to increase fuel efficiency and performance, with the UX 250h being prioritised in EV mode. Toyota perseveres with NiMH, rather than following the industry norm with Lithium-ion battery technology, for two sound reasons: a) Lithium is a natural resource that is also proving more difficult to mine and b) NiMH is less volatile. Yet, the company uses Li-ion types now in other models. Working with its battery partner, Panasonic, the UX’s battery features
a more compact cooling system and also new but (at the moment) secret electrode material. It comprises 180 x 1.2V cells, giving a total voltage of 216V and an output of 24kW. It is located beneath the UX’s rear seat, not spread across the whole floor pan, which serves to minimise intrusion in the boot and contributes to the car’s improved front/rear weight distribution and lower centre of gravity. 


The Fourth generation of petrol- electric hybrid drivetrain.

The new E-Four all-wheel drive system uses a dedicated (third) electric Motor/Generator integrated with the rear differential. Compared to previous Lexus AWD systems, the rear hybrid transaxle has been reduced in size and weight significantly, which improves both luggage space and the car’s handling agility and stability. As is typical, it uses sensors to monitor wheel speed, G-forces, yaw rate and steering angle. The front- to-rear torque split can vary from all-front, to a more rearward 20:80, which aids dynamic balance significantly. Steering feel is both more precise and reactive. E-four also aids stable driving on uphill slopes, or snow-covered roads, while fuel consumption is claimed to be around 12% improved over former two-motor developments. 


The engineering team at Lexus sought to reduce weight, with the intention of improving the UX 250h’s efficiency and performance. The new engine is one of the lightest in its class, weighing a mere 112kg (a Prius engine tips the scales at around 117kg). A further 27kg was saved by using aluminium, in place of steel, for the vehicle’s doors, wings and bonnet, with a lighter composite material used to construct the tailgate. The aluminium internal tailgate frame, with outer and inner panels made of Super Olefin Polymer is another Lexus first. These weight-saving measures result in the UX having the lowest centre of gravity of any vehicle in its class. 

Hyundai Ioniq Electric (AE-EV) (2016-Present)

Introduced in 2016, the Hyundai Ioniq is available in hybrid, plug-in hybrid and all-electric variants. Because the electric version has a much larger battery than its hybrid stablemates, it does away with the usual independent rear suspension in favour of a simpler beam axle. The Ioniq Electric uses a 88kW electric motor and a 28kWh battery. The Ioniq EV’s superb aerodynamics, thermal management and electric drivetrain helped it to become the most energy-efficient car ever tested by the US EPA, with the hybrid and plug-in versions also offering impressive economy figures. This article only covers the electric version which is distinguished by a smooth grey front end.


The electric version of the Ioniq has a 360V Lithium-Polymer battery pack. The useable battery capacity is 78 Ah/28kWh. There are six 6-cell modules (numbered 1, 2, 3, 10, 11, 12), and six 10-cell modules (numbered 4-9).

Thirteen voltage protection devices (VPD) are located around the battery pack. These are physical switches that are disconnected if a battery module physically expands due to overcharging. In this case, the high voltage system will be switched off and the car undriveable.

The high voltage contactors are located within a Power Relay Assembly- one for the negative and a main and pre-charge relay on the positive side. Pre-charge resistor spec is 40 Ohms. The PRA also contains the two relays for rapid charging (QRA) and for battery heating.

The battery pack is air-cooled. A fan in the offside rear of the vehicle pulls air through the pack from air vents under the rear seats.

The driving power will reduce as the battery state of charge gets low to prevent high current draw at low SOC damaging the battery pack. As with all EV batteries, the full capacity is not used- 28kWh is the useable figure, with the whole capacity being a little larger. Some capacity is also kept back and is used to mask degradation.

Battery charging

The Type 2 CCS charging connector is located on the nearside rear wing. The liquid- cooled OBC (On board charger) is located under the bonnet, sandwiched between the EPCU and the motor.

A Charge Control Module is located under the front passenger seat. It converts the PLC communication from the external charging post into CAN that can be understood by the rest of the car. Charging speed is 6.6kW on AC, and 100kW on DC CCS, although there are not currently many charging stations in the UK that can supply more than 50kW.

Three blue charging indicator lights are fitted on top of the dashboard. The operation of these is similar to that of the Nissan Leaf but not quite the same. During charging, the first light will flash until the battery reaches approximately 1/3 full, at which point the first

light will be on solid and the second light flash, and so on. All three lights on means the car has just finished charging. All three lights flashing means a charging error has occurred. The centre light flashing means a charging timer is set. The end light flashing means the 12v battery is charging, either for a top up, or because remote climate control is on.

The red dashboard warning light indicates charging in progress, and turns green when complete but still plugged in.


A 88kW permanent magnet three-phase AC electric motor is used, with inverter built into the EPCU. When replacing the motor or EPCU, it is necessary to carry out Initialisation of Automatic Resolver Offset calibration. The cooling system is bled via diagnostic equipment.

Cabin heating and cooling

An electric compressor is used, and a heat pump in addition to a PTC heater. The PTC heater runs from the high voltage system. The PTC heater has a high-voltage interlock circuit which appears to be joined to the HVAC ECU, and then sent over CAN. This would suggest a fault in the HVAC ECU or its network would cause a non-start, although we have not been able to verify this at the time of writing.

The refrigerant circuit is as follows. The system can collect waste heat from the high- voltage cooling system, making it more efficient.

When in cooling mode, the system operates like this. With the various valves in these positions, the system operates the same as any other air-conditioning system. Flaps in the car (not shown) divert the air away from the internal condenser. The internal condenser therefore effectively just acts as part of the pipework. The heat is given up at the front of the car, and passed through an expansion valve to cool the evaporator.

When in heating mode, the valve positions change. The valve shown at the top of the diagram is now closed. There is now a pressure change in the internal condenser, causing the heat to be “dropped” here. The now-cool refrigerant then goes on to collect heat from outside air, and from the heat exchanger (which Hyundai calls the Chiller). The evaporator is now out of the circuit.

For demisting, it is advantageous to operate the heating and air conditioning at the same time. The Ioniq has another trick up its sleeve here. The valves are operated as follows:

This arrangement allows heat to be collected in the car, and dropped in the car. This can demist the vehicle with minimal operation of the PTC heater.

You will notice there is a condenser bypass valve that is in the same position in all the diagrams. This is opened if excess refrigerant is accumulated in the condenser.

Electrical system

A DC-DC converter (known as LDC) is built into the EPCU (inverter). The 12v battery is charged when the vehicle is in ready mode, when charging, and when pre-heating/cooling.

There is an option in the menu for Aux Battery Saver+ (under User Settings > Other features). When enabled, this will automatically charge the 12v from the high voltage battery as required, preventing a flat 12v battery albeit losing a little from the main battery. Aux Battery Saver+ operates for a maximum of 20 minutes at a time, and if the car is unplugged, will check on the battery every 72 hours. If it operates for ten times in a row, the system is disabled as there is either a parasitic drain or the 12v battery is faulty. A dashboard message will tell the driver the battery saver has been used since last parked.

A synthesised noise is created by the car, known as VESS. The Ioniq features various driver assistance systems. These are not covered by this guide or by HEVRA Support at this time.

Braking system

The braking system consists of a Pressure Source Unit (PSU), and a Integrated Brake Actuator Unit (IBAU) on the master cylinder.

The PSU generates and stores hydraulic pressure at approximately 180 bar, and feeds it to the IABU. The IABU can send this to the calipers when regenerative braking cannot provide the necessary brake force. The IABU also handles ABS and ESP functions, emergency backup (hydraulic link to pedal), and simulated pedal feel. A stroke sensor on the pedal measures driver demand- this must be recalibrated whenever it or the IABU is replaced.

If it is necessary to release the pipework between the PSU and IABU, use diagnostic equipment to release the hydraulic pressure. Stroke sensor calibration should be carried out on refitting. In the event of a total failure, a valve within the IABU connects the pedal to the wheels to provide braking on all four wheels with no servo assistance.

Noises from the brake pump when opening the driver’s door, repeatedly pressing the brake pedal, or pressing the pedal particularly hard are all normal. Brake bleeding is quite an involved procedure- see Hyundai factory brake manual.

Further information

Warranty information:

Standard vehicle warranty: 5 years/unlimited miles

EV battery warranty: 8 years/124k miles

Theoretical Layout

Note: Procedures described are for guidance only. Refer to vehicle manufacturer’s technical information for up-to-date procedures. HEVRA cannot take responsibility for injury, malfunction or accident.


Regenerative braking

Peter Melville looks at the brake systems used in hybrid and electric vehicles and the implications to servicing.

Whenever hybrid and electric vehicles come up in conversation, there’s often a lot of talk about high voltages, but less so about some of the other differences between these cars and traditional models, such as the brakes. 

There are two reasons hybrid and EV brakes differ from those on traditional cars. Firstly, whether it is provided by the suction of the engine’s intake system or via a mechanical vacuum pump, an engine provides a source of vacuum for brake assistance. In a car with no engine, or where the engine only runs intermittently, this is not an option. 

The other reason is that with an electric motor attached to the wheels, we can use this to slow the car. Given the choice between wearing down the friction brakes or getting a bit of free fuel, the regenerative braking is the preferred option. 

So how does this all work? A three-phase motor generator is mechanically linked to the wheels. When we apply a three- phase current to the motor, it drives the wheels. But if the motor is turning without being powered, it acts as a generator. If we provide a path from the motor windings to the battery, we can slow the car down whilst gaining some battery power. The car’s power electronics can handle any necessary voltage change, and via Pulse-Width Modulation (PWM) we can alter the amount of regeneration provided. 

It is essential for the car to be able to control the amount of regeneration for several reasons. Firstly, the battery cannot accept power under all circumstances. It is limited in terms of its overall capacity – if the battery is already full, regenerative braking is not an option. It may also be limited in current flow, for example, at very high or low battery temperatures. The battery may have spare capacity, but can only accept current at a lower rate. Regenerative braking also needs to be predictable for road safety reasons. 

Where regenerative braking cannot provide sufficient braking force, the friction brakes need to be used. Manufacturers use various systems to do this, but they all measure the driver’s braking demand and calculate how this can be split between regeneration and friction braking. Pressurised brake fluid is sent to the calipers when required. 


What does this mean for us in a repair environment? The most noticeable difference is that brake pads simply don’t wear out in the way we are used to and a side effect of this is far less brake dust on the wheels. You’d also be forgiven for thinking the brake discs rust instead, but as the friction brakes are used at low speeds, and most manufacturers build brake-cleaning functions into the software, this doesn’t really happen either. However, whilst pressure from the brakes cleans rust from the disc, the lack of heat causes moisture to collect and calipers, and associated components, are often more corroded than you may expect. When servicing, it’s essential to ensure the brakes are free, as binding brakes may have a noticeable effect on driving range. 

We also need to think differently about some other jobs. We’ve spent the last hundred years using pedal feel as an indicator as to the health of the braking system but when the pedal isn’t connected to the hydraulic system, this test becomes meaningless. 

Most manufacturers recommend replacing the brake fluid every two years and this is no different for electric and hybrid vehicles, however, the argument for doing so is stronger. With, in many cases, no hydraulic connection between the pedal and the wheels, old fluid can be a hidden danger and no clue provided by the pedal feel. Also, the cost of the electronic parts of the braking system means allowing moisture to collect becomes a potentially expensive gamble. 

The procedure for changing brake fluid depends on the vehicle. Some are similar to traditional models, yet others involve a complex process. As with many modern systems, it indicates the importance of following the correct procedures. 



HEVRA vehicle profile: Volkswagen e-Up! (2013-present)

The Hybrid and Electric Vehicle Repair Alliance provide a technical overview of the electric version of the VW Up! 

Introduced in 2013, the electric version of the VW Up! hasn’t been a huge success in the UK. Original models were known internally as BE1. 2017 brought a minor update and a new designation, BE2. The Up! was designed to be built as both a petrol and electric car. The EV uses a different floor pan to the petrol version, allowing the high voltage battery to take up space under the floor. Further modifications to the floor and body offer protection to the battery and high voltage cabling. In the absence of engine noise, rear wheel arch liners are fitted and extra soundproofing is added in the front wheel arch area. 

Dealer support for the e-Up! is pretty poor, with very few dealers offering sales, servicing or warranty repairs, which is partly why we believe independents have an opportunity. 


e-Up! has a 18.7kWh Lithium-Ion battery and 3.6kW on-board charger and Type 2 connector. Some models have DC rapid charging via CCS. The battery pack does not have a cooling system. 


The e-Up! uses a 270, LS1 motor with engine code EABA, and single-speed gearbox 0CZ. If the motor, EV ECU or inverter are replaced, reprogrammed or reset, the motor will need to calibrate before operating correctly. This will happen automatically the first time the vehicle is driven, but the car will drive with reduced power until the calibration is complete. 

The gearbox uses a mechanical parking lock operated by a cable from the gear selector. 


The e-Up!’s DC-DC converter is built into the inverter assembly. The vehicle uses a VAG generation V immobiliser. The components of the immobiliser are the Motor Control Unit (J623), EV control unit (J841) and the instrument cluster (J362 inside J285). 

With the exception of the curved LED front DRLs, the lighting system is the same as other versions of the Up! and uses traditional filament bulbs. 

e-Up! may also be fitted with a 12V heated front windscreen. 


The e-Up! uses an app called e-Manager to see battery state- of-charge, switch on remote climate control and change charging settings. These functions are controlled in the car by the Emergency Call control unit J949, also using location information from the navigation system sent via CAN. 


The e-Up!’s cooling system is in some ways similar to that of a combustion engine. One half of the cooling system pushes coolant around the inverter, charger and motor, and of course radiator, whilst the other half pushes coolant through the high- voltage PTC heater and heater matrix. The two are, however, linked by sharing the same expansion tank. Coolant used is G40. 

Air conditioning is standard which, of course, uses a high- voltage electric compressor. 


The e-Up! features an artificial noise generator behind the front grille. This is controlled by ECU J943, located under the passenger seat. 


The e-Up! uses an Electromechanical Brake Servo known as eBKV, with a pressure accumulator. The accumulator contains a pump and is used to optimise regenerative braking in conjunction with dual position sensors on the brake pedal. Discs brakes are employed on the front, with drum brakes on the rear. 

Brake fluid can be changed or bled using a 2-bar pressure bleeder. The procedure is standard, with the exception of an additional brake bleeder on the pressure accumulator. This should be bled once the four wheel brakes have been bled. 


Service history records are updated online at This URL is also used for technical information. You will need to create an account and wait for an email reply before you can log in and use the service. 

Standard vehicle warranty: 3 years/60k miles (unlimited mileage for first two years)
HV Battery warranty: 8 years or 99,360 miles, does not cover degradation 


High Voltage disconnection requires diagnostic equipment. Select the disconnection procedure and follow instructions given. In an emergency, follow instructions in emergency response guide (pull out labelled fuse). 



Thanks to Peter Melville at the Hybrid and Electric Vehicle Repair Alliance for this information. Enquire about membership and training by emailing 

Note: Procedures described are for guidance only. Refer to vehicle manufacturer’s technical information for up-to-date procedures. HEVRA cannot take responsibility for injury, malfunction or accident. 



Vehicle Profile: Mercedes Benz E300 Bluetec Hybrid [2012 – 2015]

Vehicle Profile: Mercedes Benz E300 Bluetec Hybrid [2012 – 2015] – By Peter Melville, Hybrid & Electric Vehicle Repair Alliance.

Based on the established ‘212’ model E220/E250 CDI, the E300 BlueTEC Hybrid adds a 27bhp electric motor to the powertrain although, unusually, retains a 12V starter motor and alternator. W212 (Saloon) models can be identified by a WDD212098… VIN, and S212 (Estate, or ‘T-Model’) WDD212298. 

The system features a 12V starter motor and alternator, plus a two-way DC-DC converter. As well as charging the 12V battery, it can charge the hybrid battery from the 12V system if required. The high-voltage motor- generator is used for starting the engine when stationary, and the starter is used when in motion. The starter can also be used for starting if the high-voltage battery charge is low. 

This article details the E300 BlueTEC Hybrid – a similar system is used in the C300 BlueTEC Hybrid and S300 BlueTEC Hybrid, and the later C300h, S300h. The earlier S400 petrol hybrid uses a similar system without the 12V starter and alternator. The later plug-in models are different again. 

Despite the name, the E300 BlueTEC HYBRID is not a 3.0-litre engine, it’s a 2.1, and does not have an Adblue system. 


The E-Class uses the 651.924 engine, the 651 being an established engine used in other Mercedes cars and Vito/Sprinter vans. Measuring 2143cc, and developing 201bhp, the engine has fuel-saving features such as a volume-controlled oil pump and demand-controlled coolant pump. The engine has twin- turbochargers in series, cooled exhaust gas recirculation, balance shafts and has the timing gears and timing chain on the gearbox end. 

Some engines were originally supplied with Delphi Piezo injectors, which have no leak-off pipes. These may have been replaced with the later version, with leak-off pipes, due to reliability problems. Injectors have individual codes for fine- tuning and these must be entered with diagnostic equipment when replacing. Injector seals are prone to leak, to prevent this, the injector and bore must be completely clean and a new sealing washer and bolt used, and the bolt tightened to the correct torque. If there is any resistance to putting the injector in the bore, the bore is not sufficiently clean and may lead to future leaks.

It has two turbochargers in series, the first designed to provide boost at low engine speeds and the second for high engine speeds. The exhaust manifold features a boost pressure control flap (Mercedes calls it ‘LRK’) which is like a throttle flap. When closed, the exhaust gas is sent to the first turbo, when open, the gas bypasses the first turbo and goes straight to the second. On the intake side, the air goes through the second turbo first and then can either go into the intake or through the first turbo, depending on the position of the charge air bypass flap.

As with most modern diesel engines there is also a throttle flap on the engine intake. This creates a partial vacuum in the inlet manifold to help draw in recirculated exhaust gas. The flap is also closed when switching off the engine to avoid the vibration caused by a diesel engine’s compression. The exhaust gas is cooled by the engine coolant and features a cooler bypass flap for when hot EGR is required (such as during a DPF regeneration). 

The engine has four valves per cylinder – eight inlet ports. One of the ports for each cylinder is covered by a swirl flap. The flaps can be closed during part-load acceleration to improve air-fuel mixing (imagine putting your finger over the end of a hosepipe – the faster flow helps mixing). At full load, more air is required, so the flaps are opened by an electric motor. 

The exhaust system is fitted with an oxidation catalyst and a particulate filter. The particulate filter catches soot produced by the engine and burns it into smaller particles during regeneration. The filter needs to reach temperatures of around 600°C to burn off the soot. This is done by hot exhaust gas recirculation, operating the glow plugs, and later injection. The late injection results in a higher exhaust gas temperature. The motor generator is also used to increase the load on the engine, which further increases exhaust gas temperature. If driving conditions permit (e.g. motorway driving), a regeneration is possible without using these extra measures. The car will normally do a regeneration whilst driving about every 500-600 miles. DPF problems should be rectified as soon as possible as further driving may cause the filter to block and need a new filter. A differential pressure sensor and back-pressure sensor are both fitted. 

The engine’s water pump can be switched on and off by a vacuum-operated clutch. Depending on coolant and air temperature, the pump can be de-activated for up to eight minutes after engine start to save energy. The thermostat is also electronically controlled. A normal thermostat with an increased opening temperature is used, with an electric heating element. The engine ECU can use the heating element to open the thermostat earlier if desired. The engine cooling system and high voltage cooling system share the same coolant and expansion tank, but a valve closes at around 60°C to prevent the engine’s hot coolant from heating the high-voltage system. 

The gearbox is a 7-speed 724.208 and has a 12V electric oil pump to operate the transmission when the vehicle is driving with the engine off. The motor-generator, or ‘electric machine’, is installed in the transmission bellhousing and is connected to the engine via a wet clutch. For starting, the gearbox can be put into neutral, and the motor-generator used to turn the engine. For electric driving, the wet clutch is disengaged and the motor- generator drives the vehicle via the gearbox. If it is necessary to start the engine during driving, the arrangement does not allow for this, so the engine is turned via a 12V starter motor and, once started, the wet clutch can be engaged for the engine to drive the wheels. 

An 12V electric vacuum pump located on the engine next to the air conditioning compressor is used to provide vacuum to the brake booster when the engine is not running. 

The Power Electronics Module is located on the lower left of the engine and incorporates the inverter and the DC-DC converter, it is liquid cooled. The DC-DC converter is bidirectional, so can charge the high-voltage battery from the 12V system if required.

The 12V alternator is used as and when required. Under normal circumstances, 12V power is provided by the DC-DC converter. If further power is needed, or a fault develops, the engine control module switches on the alternator over a LIN network.

If the driving conditions and battery charge permits, the engine will be switched off. Before switching off, the system checks the electric transmission oil pump is working. Start-Stop is disabled if the bonnet is open or if the engine is not at operating temperature.

The engine is shut off whenever it is not needed at speeds up to 100mph so, even if the cruising speed is high but only a small amount of power is needed to maintain cruising speed, the engine will be switched off and the motor-generator will provide the power needed.


The 23kg Lithium-Ion battery is just 0.8kWh, but this is not a plug-in vehicle, so the battery’s only function is to store energy for use later on. The battery is on the nearside corner of the engine bay and is cooled by the air conditioning system. The battery ECU and system main relays are inside the unit. An interlock circuit travels from the high voltage battery to check the presence of its high-voltage connector, and that of the Power Electronics Module, Motor-generator and the air conditioning compressor. 


Service A: £650, Diagnostic check: £162, Front brake pads and discs: £431, Rear brake pads and discs: £437, Front wiper blades: £55

To receive the full overview, which also details the Air Conditioning, High Voltage cooling, Electrical & Braking system, please email:


NOTE: Procedures described are for guidance only. Refer to vehicle manufacturer’s technical information for up-to-date procedures. HEVRA cannot take responsibility for injury, malfunction or accident.



Autotechnician’s Big Day Out heads to Nottingham

You will have seen in the July/August edition of Autotechnician that Andy Crook and James Dillon challenged and amused a room full of technicians at Reading College back in June as part of our Autotech campaign to support independent technicians in their quest for knowledge! Well, we are happy to announce the entertaining duo are set to impart as much knowledge as possible regarding the diagnostic process once again at EMTEC in Nottingham on Saturday 27th October.

The interactive day will focus on a set of live faults on a vehicle and will challenge the way you approach finding issues. The day is suitable for anyone involved in diagnostic work, providing valuable tools to take back to your workshop on every step of the process – from booking in jobs (and those best left alone), charging for diagnostics, what to test and what to expect, eliminating possible faults and customer communication.

We will also have Cleevely EV and Peter Melville of HEVRA joining us, highlighting the business opportunities of Hybrid & EV repair, with the opportunity of experiencing the ride of a Tesla Model S.

Kim D, who has undertaken diagnostics for many moons, had this to say about his experience of the last Big Day Out at Reading: “At first I thought there can’t be much to show us on an old Ka. Well there’s one thing I got wrong straight away! I liked the twists and turns of the diagnostic processes.

“It was just like real life because we as technicians do need to step back sometimes and use a different approach. Something the ACtronics guy said about a large number of control units being sent into them and when tested found to be OK… That KA with a grounded 5V ref could well be an example of wrongly diagnosing a faulty PCM. Also, something James said years ago sticks in my mind and I use this thought – ‘if you have just decided a component is at fault, you need to say to yourself, “if this doesn’t fix it, what tests would I have to do then?’ It’s at that point I would be doing those checks.”


The final Big Day Out event for 2018 will be held at EMTEC College, Mere Way, Ruddington Business Park, Nottingham, NG11 6JZ on Saturday 27th October from 9.00am to 4.30pm.

Thanks to our sponsors, tickets are available at the discounted rate of £69.50, which includes all refreshments, lunch and parking. Email: or call Nicola on 01634 816 165 to book your ticket today.

Please Note: Numbers are limited, so book your place as soon as possible if you can make the date.


Stand out from the crowd and invite hybrid repair into your workshop

You may be sitting on the fence when it comes to preparing for Hybrid & EV repair, perhaps unconvinced by the numbers on the road, the considerable infrastructure required if we all decide to take the greener option, or you simply don’t rate them and fail to see the need to tool up and train until customers start demanding it. All valid points, of course, but although the numbers are still relatively small, the take up of new and second-hand electrified vehicles is rising significantly. Perhaps if customers knew you could undertake this work, you’d find a number of customers have been taking their plug-in elsewhere for repair and maintenance. Autotechnician will highlight a few individuals and workshops who are leading the way and creating a future-proof business that sets them apart.

Here, we meet Peter Melville, who has established the Hybrid and Electric Vehicle Repair Alliance, a support network that provides a recognised standard for garages offering hybrid
and electric vehicle servicing and repairs. Members must meet specified standards for training, tools, test and safety equipment and HEVRA provides access to data, technical support, advice and ongoing training.

HEVRA exists to help garages make the transition to electric cars

Peter’s day job is tackling the diagnostic side of things at Nev’ll Fix It, a thriving independent workshop in Tonbridge. Last year, he needed to purchase a reliable commuter car and he went for a plug-in Vauxhall Ampera. There was a problem with the air con and the local dealer wouldn’t touch it, the nearest one that could provide service and repair was over an hour’s drive away. He realised the opportunity and grabbed it with both hands. In January he set up HEVRA to help other garages move into this arena and it now supports over 20 garages across the UK.

“Part of what we do, is training. The course I run in Tonbridge provides everything a technician needs to know for servicing, repairs, and some basic fault-finding, for minimum cost and inconvenience. We also offer packages, where people can also pickup the required tools when they attend the course, so they can get straight into when they get back to work.” Peter is keen to point out that he doesn’t want HEVRA to become an exclusive club for people who attend his training. Every garage and mobile mechanic is able to join, as long as they meet the required standard (must haves include air con equipment for R134a and R1234yf with hybrid vehicle function, a Cat III multimeter with Cat III leads and at least two pairs of Class O electrical gloves – there’s a list available on the website). “HEVRA membership is not about being able to do everything – it’s about doing what you do to a high standard,” explains Peter. “Most of our members do in-depth diagnostic work on hybrid and electric cars, but some just do routine servicing and general repairs. There’s a misconception that the drivetrain is the only difference compared to traditional cars but there’s all sorts of things – brakes, air con, even tyres.”

Members are listed on its professional register and receive marketing support and regular newsletters with technical content, including comprehensive overviews of particular models, such as the Nissan Leaf, info in the following pages. It is currently free to join with no ongoing costs but later this year, Peter plans to introduce a monthly fee which will be around £25 to cover his time and expenditure. He comments: “Hopefully you’ll decide the membership benefits are worth the cost and stay with us. If not, you can leave whenever you like with nothing to pay.”




In the September issue of Autotechnician, we’ll talk to Cleevely Electric Vehicles, the first independent garage within Gloucestershire to become HEVRA and Go Ultra Low accredited who offer an EV rental service and a cost-effective alternative to main dealerships.

HEVRA Vehicle profile

Note: Procedures described are for guidance only. Refer to vehicle manufacturer’s technical information for up-to-date procedures. HEVRA cannot take responsibility for injury, malfunction or accident.

Introduced in 2010 in Japan, and 2011 in the UK, the Nissan Leaf (which stands for Leading Environmentally-friendly Affordable Family car) is the most popular all-electric vehicle on Britain’s roads. With a distinctive bug-eyed appearance and finned headlamps to reduce wind noise, the combination of relatively low cost, reliability and Nissan’s dealer network has proved a hit with EV buyers. Many Leafs are bought new on PCP or Lease, with the fuel savings covering the monthly payments. In March 2013, Nissan brought Leaf manufacturing here to England, building the car on the Qashqai line and sharing the Sunderland factory with the Note and Juke models, with the high voltage batteries also made locally. At the same time, Nissan updated the car with a new black interior (early models were beige), improved battery, heating system, new trim designations (including a new cheaper ‘Visia’ model) and a foot-operated parking brake replacing the electric parking brake on all models. Early Japanese-built models, model code EM61, will have a VIN beginning with J, UK-built cars are model code EM57 and the VIN will start with S.

Under the bonnet, 2013-on (EM57) models are faced with the Power Distribution Module housing the on-board charger, DC-DC converter for 12v battery charging, air conditioning relays, DC charging relays and charging fuses (note the fuses should only blow in exceptional circumstances- to replace them involves discharging the high voltage system and removing the PDM cover which is held in place with sealant). Under the PDM lives the inverter, and beneath that the motor, reduction gear and differential. Early (EM61) models have just the motor and inverter underbonnet with the charger located in the rear of the vehicle.


The Leaf was launched with a 24kWh battery- this is the total capacity, and as with all traction batteries, the very top and bottom of the battery are not used, so the useable capacity is a little less. 2013 brought an updated battery of the same capacity but designed for reduced wear, and this does seem to be an improvement. From 2016 a 30kWh battery was available as an option, with the vast majority of buyers going for the larger version. 30KWh variants can be identified by their higher gross weight on the VIN plate (1970kg compared to 1945kg).

Unusually, the Leaf has no battery cooling system, but instead has battery cells that are designed to absorb heat without affecting their short-term or long-term health. This strategy seems to have worked well for Nissan in the UK and Northern Europe, although in hot parts of the US many Leafs have suffered from early battery degradation. Battery degradation on the Leaf is a normal part of ownership, although it happens slowly and gradually, with many cars over 100,000 miles covering significantly less miles per charge than when new, although still enough to make it a useable car for many drivers. The battery’s health can be checked from the driver’s seat using the battery capacity bars up the side of the battery charge gauge- 12 bars being the full quota and the first bar disappearing when the battery gets to around 85% state of health.

The lack of battery cooling system means the Leaf is one of few EVs on the market with a battery temperature gauge- as a rough rule of thumb expect three bars in winter, four in spring/autumn and five in summer, with driving and charging both increasing the temperature. Long trips with fast driving and rapid charging will result in higher readings, with 24kWh versions being able to dissipate heat a little better than the denser 30kWh battery. In the event that the battery temperature is too high, with no cooling system to check the only thing that can be done is check the three temperature sensors are reading correctly and allow the car to cool over a period of time. High battery temperatures will cause reduced motor power and reduced charging speeds, although only extreme use will cause these symptoms.

Battery ECU and System Main Relays are all located in the battery case, however opening the case will void the battery warranty.


The Leaf offers two charging options- a Type 1 connector for AC charging, and a CHAdeMO for rapid charging, rated to 3.3kW AC and 50kW DC respectively. A faster 6.6kW charger was available as an option, which of course needs a 32A supply and cable in order to make use of the higher speed. The charger on early models was behind the rear seats, which was moved under the bonnet for 2013 models. You can determine the charger fitted by using the trip computer buttons to cycle through the display in front of the driver. When the charging time is displayed, models with the optional faster charger will show different times for 3.3kW and 6.6kW supplies. The CHAdeMO DC charging connector was not standard on the “Visia” base model.

Pre-2016 models had an option to limit charging to 80%. If a customer complains that charging is not finishing this is the first thing to check (set within the touch screen menu by pressing ZeroEmission button). When rapid charging from less than 50% full, the charging will stop at 80% full unless restarted. This function was deleted with the 2013 update so later cars will charge from empty to full normally.

EM57 (2013-on) models have an electric release on the charging port, operated by holding the button in the car or on the key fob.

A charging timer is fitted on all models to allow the vehicle to charge at a convenient time or make use of off-peak electricity tariffs. The times are set through the touchscreen by pressing the ZeroEmission button. If just an end time is set, the vehicle will estimate the charging time and start at the required time to make sure the vehicle is charged by this time. The clock used is the same as the one displayed, so any error in the clock time will affect the charging timer. A timer bypass button is fitted to override the usual schedule if the vehicle needs to be charged straight away.

Three blue charging indicator lights are fitted on top of the dashboard. During charging, the first light will flash until the battery reaches approximately 1/3 full, at which point the first light will be on solid and the second light flash, and so on. Lights coming on alternately as if scrolling across means the charging cable is connected but charging has not started as the charging timer is set. If the third light is blinking when the charging cable is unplugged, this indicates the remote heater or air conditioning is operating, or the vehicle is topping up the 12v battery. The centre light on solid means the vehicle’s charging timer has been bypassed and the vehicle will charge as soon as the supply is connected.

The Leaf has an unusual gear selector between the front seats- little pad moves towards the driver for Drive, and towards the front for Reverse, with a little park button on top. To select Neutral, the selector just needs to be held to to the centre right for a second or so. The gear selector is entirely hall-effect with no physical switches- so attempting to clean it is probably a waste of time unless the movement is physically restricted by debris. Six sensors built into the selector all switch from 0v to 5v and the car uses this to determine the selector position. If the customer complains of a delay in selecting drive, check for fault P0705 which is an indicating of a hall-effect sensor not switching and may indicate a faulty selector assembly. The other issue if a customer says they cannot select gear is to make sure the car is actually on rather than just ignition on.

Moving the selector towards the D position when already in Drive will alternate between D and B (Brake) modes- with B offering a higher level of regenerative braking. D and B can be switched at any time, including when driving.

All Leafs use a proximity key with keyless entry and keyless starting. A blade can be withdrawn from the key for emergency use. There is also a backup transponder ring by the start button, so if the key is completely flat, the vehicle can be started by holding the key next to the start button when trying to start.

Acenta and Tekna models have a colour touchscreen with sat-nav as standard. In order for this and the audio system to function, the SD card must be present, and these are VIN specific so cannot be swapped between vehicles. The screen has a button at the bottom right- press to open or hold to adjust the angle it sits at. The SD card is visible when the screen is open.


All Leafs have air conditioning, driven by a high voltage DC compressor, and a PTC heater also driven by the high voltage system. The PTC (positive temperature coefficient) heater element increases in resistance as it warms, reducing the current flow. The PTC heater is also PWM controlled to reduce the heat as required. All Leafs have electronic climate control which aims to reduce wasteful use of the heater and air conditioning as well as improving passenger comfort. Cabin filter is in the heater box and accessed by removing the glovebox or reaching up behind it.

EM61 Models (2010-2013)
Between the nearside headlamp and the 12v battery is the majority of the heating system, consisting of the 5kW PTC heater (high voltage), header tank, and PWM-controlled 12v heater circulation pump. The pump pushes coolant through the PTC heater assembly, which contains four separate elements and its own control system, connected to the climate control ECU via a LIN network. From there it goes through a temperature sensor, into the heater matrix, header tank and then back to the pump inlet. Apart from the high voltage compressor, the air conditioning system is entirely conventional and is of the thermal expansion valve type.

EM57 Models (2013-2017)
2013-on models have a PTC heater directly heating the air in the heater box, and also use an air source heat pump to improve the efficiency of the heating system (not on “Visia” base model). This uses existing air conditioning components to pull heat from outside to warm the interior, effectively air conditioning in reverse. Switching on the heater should increase the A/C compressor current when looking in live data- if it does not then suspect low refrigerant or a system malfunction. The compressor is located under the bonnet where one might expect the cam pulleys to be on a combustion engined car, and is powered by the Power Distribution Module, not the inverter.

The heat pump functions as in the diagrams below. In cooling mode, the valve shown at the top of the diagram is open, which means the system functions as normal air conditioning system.

The valve closes when the system is in heating mode. The refrigerant flows in the same direction, but now there is a pressure drop, causing a temperature drop. This means the (now cold) refrigerant absorbs heat from the ambient air, and with the compressor increasing the pressure again, it can drop the heat inside the car.








Climate control can also be set by a timer on all models, and by an app on all models except Visia. It’s worth noting the desired temperature is not related to the current setting in the car, but it set via a separate menu within the touch screen. When plugged in, the car will draw power from the mains to keep the battery full, however on cars with the standard 3.3kW charger owners may notice a small drop in battery charge as the heater consumes more power than the charger can provide. The remote climate control will operate for two hours if plugged in, or 15 minutes when not plugged in. During remote climate control, the car will also charge the 12V battery.


The Leaf unusually has a standard lead acid 12V battery, presumably because it is easier to share the same type as its petrol stablemates. Because of this, it is one of the few electric vehicles that is capable of jump-starting a petrol engine if required. The Leaf can also be jump-started itself if the 12V battery is discharged. Battery charging is via a DC-DC converter which is located in the Power Distribution Module on 2013-on models. An optional solar panel on the rear spoiler also feeds the 12V battery and is easily tested by disconnecting the battery leads and testing for voltage still present at the cables when the panel is exposed to daylight. Battery charging is switched on at all times when the vehicle is on, also when remote climate control is running and sometimes as required when the vehicle is at rest. Battery charging will not occur within the first hour after switching off. It is recommended that if you need to disconnect the battery, this is done between five minutes and one hour after switching off the vehicle. If necessary, restart the vehicle, switch off and wait five minutes. If you need to disconnect the 12V battery, cover the solar panel if fitted to ensure it does not keep the 12V system live.

The 12V battery is the most common cause of electrical problems on the Leaf, including starting problems, power steering problems, and “T/M System Malfunction” warnings.


The Leaf uses a 12V electric power steering system. Vehicle speed and start signal are CAN networked from the brake control module and vehicle control module respectively. The motor, gearbox, torque sensors and ECU are all built into a self-contained unit on the steering column.


The Leaf creates an artificial whirring sound to warn pedestrians of an approaching vehicle, modelled on a Japanese commuter train, known as Vehicle Sound for Pedestrians (VSP). The VSP control module behind the glovebox receives vehicle speed and gear information via CAN from the Vehicle Control Module and drives the speaker behind the front bumper. It also makes the beep when connecting the charging cable, and controls an additional speaker under the instrument cluster for the startup sound. The buzzer for the brake warning is controlled by the brake control module.


The motor, inverter and PDM all share a liquid cooling system, with a conventional header tank, radiator and radiator fans. A variable-speed electric water pump mounted on the driver’s side of the engine bay pushes coolant down through the PDM, then inverter, then motor and up through the radiator. The pump should not be run with no coolant in the system.

The system can be bled by filling the system, then using diagnostic equipment to run the pump for one minute. If water can be heard flowing in the PDM area, run the pump until the sound goes away. Check the level is on the maximum.

The coolant temperature sensor is located in the top left corner of the radiator. There is no thermostat fitted. The water pump is operated by the Vehicle Control Module (VCM). The cooling system is pressurised to 0.3 bar- use this as a maximum if you need to pressure test the system.

EM61 Leafs with the on-board charger in the rear of the car still use a water cooled charger. Coolant pipes run the length of the car in the “transmission tunnel”.

The battery pack is not cooled (see Battery).


The Leaf’s braking system consists of a electronic master cylinder containing a motorised piston. When braking is required, the brake motor operates a screw that pushes a hydraulic cylinder, pushing fluid to the calipers in the usual way. Driver brake demand comes from a stroke sensor on the pedal. The Electronic Brake Unit and the Vehicle Control Module communicate via CAN to establish how much of the braking can be done by regeneration, and how much requires the friction brakes. Friction brakes are used exclusively when the battery is full, with regeneration also dependent on ambient temperature and vehicle speed. The Electronic Brake Unit then operates the motorised master cylinder to push fluid down to the calipers. If the power supply fails, a backup power supply unit in the rear of the vehicle provides electrical power to the braking system. There is a further backup in the event of total failure which connects the pedal to the master cylinder and operates as a conventional hydraulic system with no assistance or regeneration.

In the event of brake problems on starting the vehicle, check for any type of device fitted in the vehicle’s diagnostic connector. These devices can drain the 12V battery and interfere with CAN communication and we strongly recommend are not left connected all the time.

The Electronic Brake Unit is one unit with the ECU, master cylinder, reservoir etc, although this only creates pressure. ABS functions are handled by a conventional ABS control unit on the other side of the engine bay, and the two are linked by their own network. A yellow warning light, a red warning light and a warning buzzer are all fitted to warn the driver of a problem, depending on the severity.

Brake fluid is normally changed every two years, and bleeding is carried out with key on, engine off (press start button without touching brake pedal until ignition lights come on). Fill the brake fluid reservoir, pump the pedal a few times, then open the bleed valve and pump fluid through as required. Nissan recommends bleeding right-hand-drive Leafs in the following order: nearside rear, offside front, offside rear, nearside front.


EM61 models (2011-2013)
Drum-in-disc operated by an EPB motor via cables. The actuator is located under the rear of the vehicle, with the control module a separate unit in the boot area next to the brake emergency power supply. Emergency release is under a cover in the boot floor (push and rotate anti-clockwise). The parking brake will only release automatically if the vehicle is in gear, accelerator depressed and driver’s seat belt is fastened. The EPB actuator position must be relearned with diagnostic equipment if the actuator, cable or brake shoes have been disturbed. Brake shoes can be adjusted via a hole in the disc- move the adjuster wheel upwards to tighten until locked, then back off 7 clicks and make sure the wheel turns freely.

EM57 models (2013-2017)
Drum-in-disc operated by a foot pedal. Brake shoes can be adjusted via a hole in the disc. Move the adjuster wheel upwards to tighten until locked, then back off until the wheel turns freely.


Many diagnostic machines will interrogate the Leaf, however many do not cover every module in the vehicle. Our preference is the G-Scan from Blue-Print. If you have a scanner that connects to the car but does not show detailed battery information, a nice little add-on is LeafSpy- not a diagnostic tool as such but a smartphone app that works through a ELM327 dongle to pick information from the vehicle’s EV CAN network. At the time of writing LeafSpy is around £15 from the App Store or Play Store and around the same again for the required ELM327 hardware.


The Leaf uses a single-speed reduction gear. Because the motor is permanently and physically linked to the wheels, the Leaf cannot be towed with the driving wheels on the ground. There is both a level plug and a drain plug on the gearbox. For the ‘gear’ selector in the car, see Driving.


Leaf wheels are 16” or 17”. The Leaf’s rear beam means rear camber and toe are not adjustable, and toe is the only adjustment on the front end. Although any tyres the right size will fit the Leaf, tyres with a poor efficiency rating will have a noticeable effect on driving range, and because of the car’s lack of engine noise, noisy tyres will be very noticeable. Our favourites are Michelin Energy Saver + S1, which have a A rating for efficiency, A for wet grip and noise rating of 70 dB, although these are not available for the 17” wheels. A nut at the base of the tyre valve indicates the car has TPMS.


The Leaf’s strut tops are prone to collecting rainwater, which will rust the mounting nut and make it difficult to remove. A rubber cover is available from Nissan (part number 54330- ED000) worthwhile persuading your customer to have a pair fitted to save pain in the future!

It’s also worth mentioning bodywork repairs- the high voltage battery must be removed before the vehicle is put into an oven. If using portable paint drying equipment, use a infrared thermometer or thermal camera to monitor the sill area- it should not exceed 60°C.

Nissan service prices: Minor service : £149 Major service: £199

Warranty information: Standard vehicle warranty: 3 years/60k miles
Lithium Ion battery warranty (against failure): 5 years/60k miles Lithium Ion battery warranty (against excessive degradation*): 24kWh models: 5 years/60k miles
30kWh models: 8 years/100k miles

In addition to standard block exemption regulations, Nissan will only honour warranties if the vehicle battery pack case has not been opened.

*excessive degradation is defined as fewer than 9 of 12 battery health bars remaining.


The dots along the top show the motor power or regeneration. The gauge on the left is battery temperature, and the green light in the centre is the “ready” light that indicates the vehicle is running and will move if put into gear. The right hand gauge is the battery level, with the slim outer lights showing the capacity (lost bars indicate a degraded battery). The estimated remaining driving range is inset into the battery level gauge (90 miles in this case). The battery percentage in the centre is not shown in EM61 models.


Area shown to right side of steering wheel. Buttons in yellow, left to right:

Blue: bonnet release. Red: diagnostic connector.












  1. Switch off the vehicle and wait 5 minutes. If the vehicle has been parked for an hour or more, start the vehicle, then switch off and wait 5 minutes. Ensure the charging cable is NOT
  2. Remove the key from the vehicle and put it in a safe place at least 5 metres
  3. Disconnect the 12v
  4. Lift the cover in the transmission tunnel in front of the rear centre
  5. Remove 3 x 10mm bolts holding the metal
  6. Check your high voltage gloves for leaks by rolling them up from the open end- only use gloves that are clean, dry and free from air leaks.
  7. Wearing your high voltage gloves, remove the service
  8. Wait 10 minutes.
  9. Unlike some vehicles, the Leaf does not have a convenient place to verify that high voltage has dissipated. Therefore when working with high voltage components, you must assume the system is still live and take appropriate precautions and wear appropriate PPE until you have proved otherwise at the component.

Note: Reconnection is the reverse of disconnection. When reconnecting the 12v battery, the driver’s window will need to be reset by winding down, holding for 2 seconds, then winding up and holding for two seconds. The clock will also need to be reset (clock time set through touch screen).

Thank you to Peter Melville of HEVRA for this information.