Operation CHARM: Car repair manuals for everyone.

P0057

12B402 - P0057

Information saved in
DME

Fault code
12B402 - P0057

Fault text
Oxygen-sensor heater after catalytic converter 2, activation:
short circuit to ground

Fault description
The diagnostic function monitors the messages from the
internal driver circuit diagnosis.

Condition for fault identification
Test condition:
The fault is recognized by the self-diagnosis.
Potential problem source(s):
- Defect in wiring harness to oxygen sensor 2 behind
catalytic converter
- Oxygen sensor 2 behind catalytic converter defective
- Defective DME
Terminal condition: none
Voltage condition:
- Electrical system voltage > 10 V
Temperature condition:
- None
Time condition:
- 0.2 sec.
Other conditions:
- Engine on
- No additional diagnostic fault codes logged

Condition for fault memory entry
This fault is logged in the control module's fault memory
immediately.

Action in service
- Check wiring harness to oxygen sensor 2 behind catalytic
converter
- Replace post-catalyst oxygen sensor 2
- Replace DME

Fault effect and breakdown warning
Breakdown notice:
- none
Possible apparent symptoms:
- none

Driver information
Warning light:
- ECE emissions warning lamp: on
- US emissions warning lamp: on
- ECE electronic engine power reduction: off
- US electronic engine power reduction: off
- CC message: none

Service instruction
- none