P0151
P0151Oxygen sensor in front of catalytic converter, bank 2 - Nernst voltage line - below limit value
Diagnostic conditions
- Battery positive voltage between 10 V and 16 V
- Time after the engine is started longer than 10 seconds
Possible cause of fault
- Check Nernst voltage line for short circuit to ground
- Oxygen sensor faulty (internal short circuit or intercore short circuit)
- DME control module faulty
Affected terminals
DME control module connector A, pin 13, oxygen sensor connector in front of catalytic converter, bank 2, pin 1
Diagnosis/troubleshooting
NOTE: Do not use contact spray on the oxygen sensor plug connections as this may cause irreparable damage to the wiring (contamination of the oxygen sensor via the reference air channel).
NOTE: Do not confuse oxygen sensor in front of catalytic converter and oxygen sensor behind catalytic converter as this will cause implausible fault entries.
Distinguishing feature of both sensors:
Oxygen sensor in front of catalytic converter (LSU) has a six-pin connector
Oxygen sensor behind catalytic converter (LSF) has a four-pin connector
