P2A01

P2A01

Diagnosis information - DME (DFI)

Fuel trim deviation behind catalytic converter, bank 1

NOTE: This fault is detected if the oxygen sensor signal behind the catalytic converter deviates so quickly and greatly (rich or lean) that the lambda control cannot balance the mixture. (e.g. hose on intake pipe has fallen off ...)
At this moment, it is not yet clear what has caused this deviation (mixture fault, electrical fault).
A further diagnosis procedure is initiated which actively checks the sensors ahead of and behind the catalytic converter by specific enrichment and weakening of the mixture. The vehicle must be driven in the same driving cycle (without ignition reset) for this purpose.

Diagnostic conditions
- Engine running more than 90 seconds
- All 4 oxygen sensors ready for operation
- No overrun fuel shutoff

Possible fault causes
- Fault in fuel/air mixture
- Fault in exhaust pipe
- Fault in exhaust measurement
- Other faults are stored in the fault memory