Harry Lewis, RMI Senior Technical Advisor, helps a workshop on the RMI helpline who is presented with a fuel trim issue.
VEHICLE: VAUXHALL ASTRA J 1.4 TURBO LUJ A14NET
Q. The engine management light on a customer’s Vauxhall Astra is on. The fault code reads P0171 – fuel trim system lean.
A. Carry out basic checks to identify if there are any induction/ exhaust air leaks. This fault could have various root causes – in this case, we had feedback pointing to a faulty evaporative emissions canister purge solenoid valve. Therefore, replacing the purge solenoid and clearing codes rectified the issue. Evaporative Emission Canister Purge Solenoid Valve (1.4L LUJ) replacement procedure: Disconnect battery negative cable.
WARNING: Fuel/petrol vapours are highly flammable. A fire could occur if an ignition source is present. Never drain or store petrol or diesel fuel in an open container, due to the possibility of fire or explosion. Have a dry chemical (Class B) fire extinguisher nearby.
Disconnect the electrical connector.
The RMI Technical Helpline is available to support technicians experiencing problem repairs, help with undocumented fault codes and guide users through wiring diagrams. For more information call the Independent Garage Association helpline on 0845 305 4230 or email firstname.lastname@example.org.