I received a panicked phone call from a customer one Friday saying that every possible warning light had illuminated on the dashboard of their Range Rover Vogue, the car was no longer driving, and various other electronic faults including a headlamp not working and the automatic tailgate not opening or closing. As the local main dealership was booked up for six weeks, he asked if I’d take a look. Oh, and one more thing… they needed the car back for the weekend. No pressure then!
I like a challenge, so I agreed to take a look for them. Within a couple of hours, the car had arrived on a recovery truck and was hooked up to the Bosch KTS. The warning lights that were showing were: Gearbox fault, stability control, suspension height, emergency brake assist, EBD fault, electronic handbrake fault, adaptive dynamics fault, engine management light and ABS light. I carried out a global scan of the vehicle which is something I am in the habit of doing on every job. This allows me to look at the whole picture of what I am dealing with. The global scan took a little bit of time and after it had finished, I had 177 fault codes spanning no less than six pages. I took some time to analyse the fault codes and spotted something of interest. The ABS module was not communicating. I decided it would be the best course of action to follow this route.
I gathered some technical information and took a moment to study a wiring diagram. I could see that the ABS module’s power was supplied by three fuses. They were easily accessible, so I checked these first, but they were all OK. I then checked the power supply at the ABS control module plug and again, this was fine. I could see that there were also two earths that required checking. I did this by load testing them with my 12V test light. Upon doing this the test light did not illuminate. Having now established the reason that the ABS module was not communicating with the rest of the network, I now had to find the root cause of the fault.
Knowing the features of the technical data was key. By hovering over the earth point (Terminal 31) on the wiring diagram it would lead me to the earth point locations. Without this feature, within the wiring diagram, I would have been looking for needle in a haystack. It gave the location of the driver’s front wheel arch. I removed the wheel and the wheel arch liner. Immediately, I could see the fault. The earth point had snapped. We carried out a repair to the earth point and plugged in the Bosch KTS again. We cleared the codes in all modules and started the car. All of the warning lights extinguished, the ABS module was now communicating, and the headlight and tailgate were working.
This is the importance of having the right tooling, technical information and a solid diagnostic routine in place. Keep your cool and take some time to analyse all the data available to you. The customer was amazed that their car came back to them in time for the weekend, especially as they had thought that their car was going to be beyond repair.