P2627

P2627

Oxygen Sensor Ahead of Catalytic Converter, Bank 1 - Pump Voltage Line - Below Limit

Diagnosis conditions
- Battery positive voltage between 10 V and 16 V
- Time elapsed after engine start-up greater than 10 seconds
- 10 seconds after start

Possible fault cause
- Pump voltage line short circuit to ground
- Oxygen sensor faulty (internal short circuit or intercore short circuit)
- DME control module faulty

Affected terminals
DME control module connector A, pin 52, and oxygen sensor connector ahead of TWC, bank 1, pin 6

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.