P0157
P0157Oxygen Sensor After TWC, Bank 2 - Below Limit
Diagnosis conditions
- Exhaust temperature between 250 °C and 750 °C
- Battery positive voltage between 10 V and 16 V
- 200 seconds after start
- No secondary air
- No diagnosis of secondary air system
- No fuel tank ventilation
- No diagnosis of fuel tank ventilation system
- No additional faults in memory
Possible fault cause
- Short circuit to ground in signal wire
- Intercore short circuit
- Oxygen sensor faulty (short circuit)
- DME control module faulty
Affected terminals
DME control module connector A, pin 10, and oxygen sensor connector after TWC, bank 2, pin 3
DME control module connector A, pin 11, and oxygen sensor connector after TWC, bank 2, 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 (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.
