This Citroen Berlingo was slightly unusal. It went for an MOT and there was no engine light visable when turning the ignition on, it was later discovered the engine light had tape over due to an on going problem with this vehicle. As with any Citroen and Peugeot these are hard to diagnose without any form of professional diagnostic equipment. We scanned the vehicle for fault codes and it has 2 codes stored within the ECU.
One code was relating to the throttle body and the other was relating to the glow plugs. We stripped the vehicle down and got to the glow plug module. All checks were carried out to confirm the glow plugs and wiring were in a good state. Once we confirmed all powers and grounds we moved onto the data commands sent back and forth to the vehicles ECU. Once we got the scope on these wires we could see communication was being sent from the ECU but the glow plug module was sending nothing back. Meaning the ECU knows their is an issue with the glow plug module. This part will have to be replaced.
The throttle body code was relating to the refrence voltage back to the ECU. The vehicle run perfect however the ECU didn’t know the throttle plate angle due to the output on the throttle body not reporting correctly to the vehicles ECU. This voltage needs to be between 0.08-5 volts. We done a bypass test via our autosim pro which allows us to create a custom 5v refrence voltage and confirmed the throttle body also required replacing.
If you would like an accurate diagnostic on your vehicle call 07340 341790. We are fully mobile in the local area.