DTC EFI-422

4-2-2 ATMOSPHERIC PRESSURE SENSOR SIGNAL





Condition

Diagnostic trouble code (DTC) EFI-422 is stored if the Engine Control Module (ECM) receives a signal from the Atmospheric Pressure Sensor corresponding to a height above sea level of over 6,500 meters (low signal) or under - 780 meters (high signal).

Diagnostic trouble code (DTC) EFI-422 is stored if the signal is unstable for 25 seconds (sporadic signal).

Substitute Value

- the engine control module (ECM) adopts a height of O meters above sea level.

Possible Source

Signal too High:

- Short-circuit to supply voltage in the signal cable.
- Open-circuit in signal or ground lead.
- Short-circuit to supply voltage in the power cable.
- Contact resistance in terminals.
- Short-circuit to supply voltage in air conditioning (A/C) pressure sensor power cable.
- Short-circuit to supply voltage in fuel tank pressure sensor power cable.
- Short-circuit to supply voltage in accelerometer power cable.
- Defective atmospheric pressure sensor.

Signal too Low:

- Short-circuit to ground in signal cable.
- Short-circuit to ground in power cable.
- Open-circuit in power cable.
- Contact resistance in terminals.
- Short-circuit to ground in air conditioning (A/C) pressure sensor.
- Short-circuit to ground in fuel tank pressure sensor power cable.
- Short-circuit to ground in accelerometer power cable.
- Defective atmospheric pressure sensor.
- Defective air conditioning (A/C) pressure sensor.
- Defective fuel tank pressure sensor.
- Defective accelerometer.

Signal sporadic:

- Loose Connection
- Contact resistance in terminals.
- Defective atmospheric pressure sensor.
- Defective air conditioning (A/C) pressure sensor.
- Defective fuel tank pressure sensor.
- Defective accelerometer.

Fault Symptom(s)

- Poor performance at high altitude.
- Can cause starting problems at high altitude.