Diagnostic trouble code (DTC) information ECM-143C
Condition
Engine Control Module (ECM) checks the signal for outdoor temperature at start. This is done by the control module saving the values from outdoor, inlet and engine temperature sensors at the moment of start. Then the control module compares the values. If the signal from the outdoor temperature sensor corresponds to a temperature that is higher than a certain limit in relation to the others, the control module interprets this as a malfunction and the diagnostic trouble code is generated.
The diagnostic trouble code (DTC) can be diagnosed after approx. 10 minutes with the engine running.
Substitute Value
- Outdoor temperature is calculated according to a model.
Possible Source
- Damaged outside temperature sensor.
- Contact resistance or oxidation in the terminals.
Fault symptom[s]
- Displays too low ambient temperature
- Displays too high outside temperature