P2231
P2231Oxygen Sensor Ahead of Catalytic Converter, Bank 1 - Heater Coupling
Diagnosis conditions
- Vehicle at operating temperature, after this 3 minutes idle speed, then approx. 30 seconds increased idle speed.
Possible fault cause
- Oxygen sensor faulty (heater coupling)
- High-resistance shunt circuits
Affected terminals
DME control module connector A, pin 5, and oxygen sensor connector ahead of TWC, bank 1, pin 4
DME control module connector A, pin 51, and oxygen sensor connector ahead of TWC, bank 1, pin 5
DME control module connector A, pin 70, and oxygen sensor connector ahead of TWC, bank 1, pin 1
Diagnosis/troubleshooting
NOTE: Do not use contact spray on the oxygen sensor plug connections, as this may cause irreparable damage to the wiring (blocking the reference air channels).
NOTE: Do not confuse oxygen sensor ahead of catalytic converter and oxygen sensor after catalytic converter as this will cause implausible fault entries.
Distinguishing feature of both sensors:
Oxygen sensor ahead of catalytic converter (LSU) has a 6-pole connector
Oxygen sensor after catalytic converter (LSF) has a 4-pole connector
NOTE: If connector A is disconnected from the DME control module and the ignition is or was switched on, the 'DME Control Module TIMEOUT' fault is recorded in many control modules.
NOTE: If control module connector A was disconnected from the DME in the course of troubleshooting or if the voltage supply was interrupted elsewhere (battery, fuse), the throttle adjusting unit must be adapted.
