Engine Controls - MIL ON/Various O2 Sensor DTCs Set
SI B12 13 09Engine Electrical Systems
March 2010
Technical Service
This Service Information bulletin supersedes SI B12 13 09 dated March 2009.
[NEW] designates changes to this revision
SUBJECT
M3 S65 - Various Oxygen Sensor Faults Stored in DME Memory
MODEL
E90, E92 and E93 (3 Series) M3 with S65 engine
Vehicles equipped with the M Double-clutch Transmission (option code 2MK
SITUATION
The Service Engine Soon lamp is illuminated, or poor throttle response is encountered. At least three of the following four faults are stored in the DME fault memory:
273A DME: Oxygen sensor vibration check behind catalytic converter, bank 1 - Signal stuck on rich
273B DME: Oxygen sensor vibration check behind catalytic converter, bank 2 - Signal stuck on lean
277C DME: Oxygen sensor trim control diagnosis, bank 1 - Integral value at max. stop
277D DME: Oxygen sensor trim control diagnosis, bank 2 - Signal offset, rich
CAUSE
The post-catalytic converter oxygen sensor harness may have been routed to the incorrect cylinder bank.
PROCEDURE
1. Remove the rear underbody protection just below the M Double-clutch Transmission, as per Repair Instruction RA 51 47 491, Removing and installing/replacing rear underbody protection. Remove the post-catalytic converter oxygen sensor connectors from their mounting cradles; pull gently downward to inspect the oxygen sensor electrical harness.
2. [NEW] Inspect the electrical harness for cylinder bank 1's post-catalytic converter oxygen sensor. The harness should be labeled with the letter "R" on a small white paper tag, wrapped around the corrugated harness protector (1).
Harness marked with an "R" = cylinder bank 1
3. [NEW] Inspect the electrical harness for cylinder bank 2's post-catalytic converter oxygen sensor. The harness signal wires should be exposed and not fully covered by the corrugated harness protector (1).
Exposed wires = cylinder bank 2
4. If the harness connection locations are correct, then reinstall the harness connectors into the mounting cradles and reinstall the rear underbody protection. Further troubleshooting will be necessary using the diagnostic tester; refer to applicable test plan for faults stored.
5. If the harness connections are located incorrectly, then the harness will need to be rerouted to the proper cylinder bank location. Use of a spring-loaded claw/retrieval tool may be required to feed the connectors to the proper locations.
WARRANTY INFORMATION