P0138

P0138

Diagnosis information - DME V6 DFI

Oxygen sensor behind cat. conv., bank 1

NOTE: Do not use contact spray on the oxygen sensor's plug connections as this will result in irreparable damage to the lines (blockage of reference air duct).

NOTE: Do not interchange the oxygen sensor ahead of catalytic converter with the sensor behind the catalytic converter as this will result in implausible fault entries.

Diagnostic conditions
- Exhaust temperature between 350 °C (662 °F) and 800 °C (1,472 °F)
- Battery positive voltage between 11 V and 16 V
- Engine idling for 200 seconds after start

Possible fault causes
- Short circuit to B+ in signal line
- Oxygen sensor faulty (short circuit to B+)

Affected contacts on the DFI control unit connector
Connector [B]:
- Contact 7
- Contact 76
- Contact 77

Affected contacts on the oxygen sensor connector behind catalytic converter, bank 1
Connector [A]:
- Contact 2
- Contact 3
- Contact 4