CDI-D OM646.8-- engine 4 cyl diesel
Symptoms
- After a short drive, the engine MIL and ESP lights turn on the instrument cluster.
- There is no throttle response.
- The engine will crank but not restart.
- If left to cool down for a while, the engine will restart
- Occasional misfire/rev limit at various engine rpm
Fault code:
P2088 Check sensor voltage 1 stored.
Possible Causes
Rail pressure sensor wiring chaffing/rubbing against aluminium thermostat housing, causing the 5v sensor supply voltage circuit to short and lose power to the following components:
B37 accelerator pedal sensor 1
B37 accelerator pedal sensor 2
B4/6 rail pressure sensor
B6/1 camshaft hall sensor
Repair Steps
- Remove engine cover to gain access to B4/6 fuel rail pressure sensor.
- Locate damaged wiring and reposition away from thermostat housing / secure with a cable tie so wiring is now situated over existing wiring and not over the thermostat.
Before

After
- Refit engine cover and erase fault codes.
- Road test vehicle to verify repair.
B6/1 camshaft hall sensor