P0056

P0056

Diagnosis information - DME (DFI)

Oxygen sensor heater driver behind catalytic converter

NOTE:
- Do not use contact spray on the oxygen sensor's plug connections (as this will result in irreparable damage to the wiring; oxygen sensor will be polluted via the reference air duct).

NOTE:
Oxygen sensors ahead of and behind catalytic converter.
- Do not interchange the oxygen sensor in front of the catalytic converter with the sensor behind the catalytic converter as this will result in implausible fault entries.
- The plugs themselves are coded and cannot be interchanged.

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

Possible fault causes
- Loose contact or corrosion on connectors or lines
- Short circuit to B+/ground/between lines or open circuit in the lines
- Oxygen sensor faulty