Signal Sporadic. Permanent Fault

SIGNAL SPORADIC. PERMANENT FAULT





Checking Diagnostic Trouble Codes

- Ignition OFF.
- Check temperature sensor connector (blue) for contact resistance, oxidation and remedy.
- Check engine control module (ECM) connector for contact resistance, oxidation and remedy.
- Temperature sensor connected.
- Engine control module (ECM) connected.
- START the engine and idle it.
- Wait 5 minutes.
- Read off diagnostic trouble codes (DTCs).

If EFI-251 is stored it should have intermittent fault status.

Alternative Intermittent:
- The diagnostic trouble code (DTC) has been caused by loose connections in the outside temperature sensor and/or engine control module (ECM) connectors.
- Then proceed to Verification section below.

Alternative Permanent:
- Proceed to test step below.





Checking Cables and Terminals

- Check outside temperature sensor and/or engine control module (ECM) connector for loose connections.
- Check cable between outside temperature sensor terminal 1 and engine control module (ECM) #A35 for an intermittent open-circuit, intermittent short-circuit to ground or an intermittent short-circuit to supply voltage.
- Check cable between outside temperature sensor terminal 2 and engine control module (ECM) #A18 for an intermittent open-circuit, intermittent short-circuit to ground or an intermittent short-circuit to supply voltage.
- Temperature sensor connected.
- Engine control module (ECM) connected.
- START the engine and idle it.
- Wait 5 minutes.
- Read off diagnostic trouble codes (DTCs).

If EFI-251 is stored it should have intermittent fault status.

Alternative Intermittent:
- Proceed to Verification section below.

Alternative Permanent:
- Try a new outside temperature sensor.
- Then proceed to Verification section below.





Verification

Hint: After carrying out the repair, check that the fault has been remedied as follows.

- Ignition OFF.
- Reconnect connectors, reinstall components etc.
- Test drive the car.
- Read off diagnostic trouble codes (DTCs).

If EFI-251 is stored it should have intermillent fault status.

Alternative Intermittent:
- Fault corrected

Alternative Permanent:
- Proceed to test step below.

Fault-Tracing Information

- The verification result shows that the fault persists.
- Do you want to exit fault-tracing?

Yes:
- Fault not corrected

No:
- Return to Checking Diagnostic Trouble Codes section above.