Diagnostic trouble code (DTC) information
Condition
Diagnostic trouble code (DTC) ECM-2820 (bank1) or ECM-2920 (bank2) is stored if the control module registers that the resistance of the front heated oxygen sensor (HO2S) in the pre-heating circuit is too high or low for a certain amount of time.
Substitute Value
- None.
Possible Source
Signal too high:
- Short-circuit to supply voltage in the signal cable
- Defective rear heated oxygen sensor (HO2S).
Signal too low:
- Contact resistance and oxidation
- Short-circuit to ground in the signal cable
- Defective rear heated oxygen sensor (HO2S).
Signal missing:
- Contact resistance and oxidation
- Open-circuit in the signal cable
- Open-circuit in the power supply from the system relay
- Defective rear heated oxygen sensor (HO2S).
Faulty signal:
- Contact resistance and oxidation
- Defective rear heated oxygen sensor (HO2S).
Fault symptom[s]
- The malfunction indicator lamp (MIL) lights.