P1009
P1009Oxygen sensors behind catalytic converter interchanged - signal implausible
Diagnostic conditions
- Battery positive voltage between 10 V and 16 V
- Relatively long drive in various operating states
- Short test "Sensor replacement diagnosis after cat"
Possible cause of fault
- Oxygen sensors behind catalytic converter interchanged (i.e. the sensor for bank 1 is inserted in the exhaust assembly for bank 2 and vice versa)
Affected pins
-
Diagnosis/troubleshooting
NOTE: This fault only occurs in relation to V6 engines.
WARNING: Always observe the notes on possible dangers, the warning and caution notes as well as the general instructions in the introduction.
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 behind catalytic converter as this will cause implausible fault entries.
Distinguishing feature of both sensors:
Oxygen sensor ahead of catalytic converter (LSU) has a six-pin connector
Oxygen sensor behind catalytic converter (LSF) has a four-pin connector
NOTE:
- During diagnostic procedures, the mixture on one bank is enriched, while the mixture on the other bank is more lean.
- This fault is detected if the oxygen sensor behind the catalytic converter indicates a leaner mixture on the enriched bank, and if the oxygen sensor behind the catalytic converter indicates a more enriched mixture on the lean bank.
Arrangement of oxygen sensors for the V6 engine
1 - Installation position for oxygen sensor BEHIND catalytic converter, bank 2
2 - Installation position for oxygen sensor AHEAD OF catalytic converter, bank 2
3 - Installation position for oxygen sensor AHEAD OF catalytic converter, bank 1
4 - Installation position for oxygen sensor BEHIND catalytic converter, bank 1