P2271

12A101 - P2271

Information saved in
DME

Fault code
12A101 - P2271

Fault text
Oxygen sensor after catalytic converter, system check:
Signal, constantly rich

Fault description
The diagnostic function monitors the upper and lower
voltage limits of the post-catalyst oxygen sensor during the
active test. The active test is started when a fault is
recognized during the trim controller diagnosis.

Condition for fault identification
Test condition:
The fault is recognized when the voltage of the oxygen
sensor behind the catalytic converter is below 0.2 V (too
lean).
Potential problem source(s):
- Oxygen sensor behind catalytic converter defective
- Leak in exhaust system upstream of oxygen sensor behind
catalytic converter
- Defect in wiring harness to oxygen sensor behind catalytic
converter
Terminal condition: none
Voltage condition:
- None
Temperature condition:
- Engine temperature > 85 °C
Time condition:
- None
Other conditions:
- Engine on

Condition for fault memory entry
The diagnostic fault code is logged if the fault remains
present longer than 300 sec. after completion of the trim
controller diagnosis.

Action in service
- Conduct system test for oxygen sensors in wrong mutual
positions
- Check wiring harness to oxygen sensor behind catalytic
converter
- Check exhaust/muffler system upstream from oxygen
sensor behind catalytic converter for leaks
- Replace oxygen sensor behind catalytic converter
- Replace pre-catalyst oxygen sensor
- 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