P0157

12AA02 - P0157

Information saved in
DME

Fault code
12AA02 - P0157

Fault text
Oxygen sensor after catalytic converter 2, signal: short
circuit to ground

Fault description
The diagnostic function monitors the voltage and the
resistance of post-catalyst oxygen sensor 2.

Condition for fault identification
Test condition:
The fault is recognized when the voltage is less than 0.073 V
and the resistance is less than 15 ohms.
Potential problem source(s):
- Defect in wiring harness
- Oxygen sensor faulty
Terminal condition: none
Voltage condition:
- None
Temperature condition:
- Engine temperature > 85 °C
Time condition:
- None
Other conditions:
- Engine on
- No additional diagnostic fault codes logged

Condition for fault memory entry
The diagnostic fault code is logged when the fault remains
present for longer than 2 min.

Action in service
- Check wiring harness
- Replace oxygen sensor

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