Fault description

Diagnosis monitors the signal of the oxygen sensor before catalytic converter and checks its plausibility against the current operating status.

The fault is recognized, if voltage of the oxygen sensor before catalytic converter is > 4.8 V (lean) during partial or full load (over a period of approx. 25 sec.)

Possible fault cause:

• Oxygen sensor not screwed in correctly
• Leak in silencer system upstream of oxygen sensor after catalytic converter
• Wiring harness of oxygen sensor defective