P2097
2C31 – P2097
Information saved in
DME
Fault code
2C31 – P2097
Fault text
Oxygen sensor before catalytic converter, trim control
Fault description
Post Catalyst Fuel Trim System Too Rich (Bank 1)
Condition for fault identification
Test condition:
O2 sensor trim control
No fault memories
Drive at 50 – 80 km/h and at moderate engine speed.
Terminal condition: Terminal 15, engine on
Voltage condition:
none
Condition for fault memory entry
Trim controller pegged
Action in service
This malfunction automatically triggers an active test
(collateral fault stored in the control module’s fault
memory!).
1. Read out results of active test (are other faults still stored
in the control module’s fault memory)? => Then continue at
this point!)
2. Initiate system test for reversed O2 sensors. Follow
instructions for system test.
3. If the system test fails to produce a result then
4. Visual inspection of wiring and plugs
5. Electrical check of wiring
260
6. Replace wiring or plugs as indicated
7. Check exhaust system forward of downstream (post-cat)
O2 sensor for leaks
8. Replace upstream (pre-cat) O2 sensor
9. Replace downstream (post-cat) O2 sensor
10. Replace control module
Fault effect and breakdown warning
