Signal Sporadic: Permanent Fault

Signal sporadic: Permanent fault

EFI-251 Outside temperature sensor, signal.

Checking diagnostic trouble codes (DTCs)












- Ignition off.
- Check temperature sensor connector (blue) for contact resistance and oxidation and remedy according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- Check control module connector for contact resistance and oxidation and remedy according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- Temperature sensor connected.
- Control module connected.
- Start the engine and idle it.
- Wait 5 minutes.




- Select Volvo Scan Tool (ST) to read off diagnostic trouble codes (DTCs).

If EFI-251 is stored they should have intermittent status.

OK - Fault-tracing information

Not OK - Checking diagnostic trouble codes (DTCs)

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Fault-tracing information
- The diagnostic trouble code (DTC) has been caused by loose connections in the outside temperature sensor and/or engine control module (ECM) connectors.

Continue - Verification

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Checking diagnostic trouble codes (DTCs)












- Ignition off.
- Check outside temperature sensor and/or engine control module (ECM) connector for loose connections according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
- Check cable between outside temperature sensor terminal 1 and engine control module (ECM) #A35 for an intermittent open-circuit according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults , an intermittent short-circuit to ground according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults , and an intermittent short-circuit to supply voltage according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
- Check cable between outside temperature sensor terminal 2 and engine control module (ECM) #A18 for an intermittent open-circuit according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults , an intermittent short-circuit to ground according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults , and an intermittent short-circuit to supply voltage according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
- Temperature sensor connected.
- Control module connected.
- Start the engine and idle it.
- Wait 5 minutes.





If EFI-251 is stored they should have intermittent status.

OK - Verification

Not OK - Replacing component

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Replacing component
- Try a new outside temperature sensor.

Continue - Verification

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Verification




Verification

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








- Ignition off.
- Reconnect connectors, reinstall components etc.
- Disconnect the Volvo Scan Tool (ST) from the VIDA station and use it in stand-alone mode.
Test drive the car.
- Use the Volvo Scan Tool (ST) to read off diagnostic trouble codes (DTCs).





If EFI-251 is stored they should have intermittent status.

OK - VERIFIED

Not OK - VERIFICATION FAILED

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VERIFIED - FAULT FOUND

VERIFICATION FAILED - Fault-tracing information

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Fault-tracing information




Information

Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Do you want to exit fault-tracing?

Yes - Exit fault-tracing

No - Attempt New Test

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Attempt New Test - Checking diagnostic trouble codes (DTCs)

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