Condition for fault identification

Test condition:

The fault is recognized when the trim control on the oxygen sensor behind the catalytic converter exceeds a level of positive 4%.

Potential problem source(s):

• Defective wiring harness
• Leak in exhaust system on engine-side of catalytic converter
• Oxygen sensor before catalytic converter defective
• Oxygen sensor behind catalytic converter defective
• Defective DME

Terminal condition: none

Voltage condition:

• Onboard electrical system voltage between 9 V and 16 V

Temperature condition:

• Engine warmed to normal temp, above 80 °C

Time condition:

• None

Other conditions:

• Engine on
• Drive at a constant speed between 50 and 80 km/h at moderate RPM (1400 to 3240 RPM).
• No faults that would cause mixture faults are registered.