P2270
2C6B – P2270
Information saved in
DME
Fault code
2C6B – P2270
Fault text
Oxygen sensor behind catalytic converter, system check
Fault description
O2 Sensor Signal Biased/Stuck Lean (Bank 1 Sensor 2)
Condition for fault identification
Test condition:
O2 sensor system check
O2 sensor voltage too high = Signal sticks at rich
Trim controller diagnosis must have been executed, see
Trim controller diagnosis. Detection of malfunctions during
the trim control diagnosis triggers the active test. Engine
running at idle is adequate for the active test;
Terminal condition: Terminal 15, engine on
Voltage condition:
none
Condition for fault memory entry
O2 sensor behind catalytic converter voltage > 0.7 V with
lean O2 data specification in active test
Action in service
This malfunction is detected during the active test. The
active test is triggered by the trim control diagnosis function
(trim controller fault code stored in the control module’s
273
fault memory!)
1. Initiate system test for reversed O2 sensors. Follow
instructions for system test.
2. If the system test fails to produce a result then
3. Visual inspection of wiring and plugs
4. Electrical check of wiring
5. Replace wires or plugs as indicated
6. Check exhaust system upstream from downstream (postcat)
O2 sensor for leaks
7. Replace downstream (post-cat) O2 sensor
8. Replace upstream (pre-cat) O2 sensor
9. Replace control module
Fault effect and breakdown warning
