P0138

P0138

02 Sensor Circuit High Voltage

Diagnostic conditions
- Battery positive voltage between 10 V and 16 V
- Exhaust temperature less than 800°C
- Oxygen sensor heating switched on for at least 120 seconds

Possible cause of fault
- Short circuit to B+ in signal wire
- Oxygen sensor faulty
- Control module faulty

Affected pins
DME control module connector II, pin 11 and oxygen sensor jack, bank 1, pin 3

DME control module connector II, pin 17 and oxygen sensor jack, bank 1, pin 4

Diagnosis/troubleshooting

NOTE: Do not use contact spray on the oxygen sensor plug connections as this may cause irreparable damage to the wiring (contamination of the oxygen sensor via the reference air channel).