Diagnostic trouble code (DTC) information ECM-29
WARNING: This page is about a different car, the 2004 Volvo S40, 2003 Volvo S40, 2002 Volvo S40, 2001 Volvo S40, and 2000 Volvo S40. However, it is still accessible from the selected car via links, so may be relevant.
Condition
The engine control module (ECM) checks the change over time from rich to lean air-fuel mixture using the signal from the rear heated oxygen sensor (HO2S). During engine braking (fuel shut-off), the fuel-air mixture is leaner. This means that the signal from the rear heated oxygen sensor (HO2S) should fall to a certain level. Diagnostic trouble code (DTC) ECM-29 is stored if the signal from the rear heated oxygen sensor (HO2S) drops too slowly or does not fall at all during engine braking.
Substitute Value
- Fuel trim disabled
- Three-way catalytic converter (TWC) diagnostic disabled.
Possible Source
- Contact resistance in the terminals
- Leakage in the exhaust system
- Defective rear heated oxygen sensor (HO2S).
Fault symptom[s]
- Malfunction indicator lamp (MIL) lit.