Diagnostic trouble code (DTC) information
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
Diagnostic trouble code (DTC) ECM-18 or ECM-1C is stored if the heated oxygen sensor (HO2S) pre-heating circuit is short-circuited to ground or voltage, if there is an open-circuit in the circuit or if the resistance in the element is incorrect.
Substitute Value
Fuel trim disabled.
Possible Source
Signal too high:
- Short-circuit to supply voltage in the signal cable
- Faulty heated oxygen sensor (HO2S).
Signal too low:
- Short-circuit to ground in the signal cable
- Faulty heated oxygen sensor (HO2S).
Signal missing:
- Open-circuit in the signal cable
- Faulty heated oxygen sensor (HO2S)
- Contact resistance and oxidation.
Faulty signal:
- Faulty heated oxygen sensor (HO2S)
- Contact resistance in the terminals.
Fault symptom[s]
- None.