P0161

P0161

Oxygen Sensor Heater Circuit Behind Catalytic Converter, Implausible Signal

NOTE: The function checks the sensor temperature (by measuring the internal resistance of the Nernst cell) dependent on the exhaust temperature. This is used to reveal deviances between the actual and target temperatures of the oxygen sensor, which implies faulty heater adjustment.

Diagnostic conditions
- DME control module supply voltage 10 V ... 16 V
- Exhaust temperature 250 degrees C ... 600 degrees C
- Intake air temperature -7 degrees C
- no other final stage oxygen sensor heater error

Possible fault causes
- plug corrosion
- Oxygen sensor faulty
- DME control module faulty