Operation CHARM: Car repair manuals for everyone.

P0031

P0031

Diagnosis information - DME (DFI)

Oxygen sensor heater driver ahead of catalytic converter, bank 1

NOTE: Do not use contact spray on the oxygen sensor plug connections, as this will cause irreparable damage to the lines (blockage of reference air duct).

NOTE: Do not interchange oxygen sensor ahead of catalytic converter and oxygen sensor behind catalytic converter as this will cause implausible fault entries.

Diagnostic conditions
- Vehicle voltage more than 9 V
- Engine running more than 10 seconds
- Oxygen sensor heater ahead of catalytic converter active

Possible fault causes
- Short circuit to B+
- Short circuit to ground
- Open circuit
- Fuse faulty
- Loose contact in connector
- Oxygen sensor faulty