Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information EFI-251

Condition




Diagnostic trouble code (DTC) EFI-251 is stored if the engine control module (ECM) receives a signal from the outside temperature sensor corresponding to a temperature below -45°C (signal too high), or higher than +140°C (signal too low) for more than 10 seconds.
Diagnostic trouble code (DTC) EFI-251 is stored if the signal is instable for 25 seconds.

Substitute value
- the engine control module (ECM) adopts an outside temperature of +20°C.

Possible source

Signal too high:
- open-circuit in signal cable or ground lead
- short-circuit to supply voltage in signal cable
- contact resistance in terminals
- defective outside temperature sensor.

Signal too low
- short-circuit to ground in signal cable
- defective outside temperature sensor.

Signal sporadic:
- loose connections
- contact resistance in terminals
- defective outside temperature sensor.

Fault symptom[s]
- none.