Signal Too Low. Permanent Fault

Signal too low. Permanent fault

EFI-251 Outside temperature sensor, signal.

Checking the signal cable








- Ignition on.
- Disconnect temperature sensor.








- Connect a voltmeter between temperature sensor connector terminal 1 and ground.

The reading should be approximately 5 V.

OK - Replacing component

Not OK - Checking for a short-circuit

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Replacing component
- Try a new outside temperature sensor.

Continue - Verification

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Checking for a short-circuit








- Check cable between temperature sensor terminal 1 and engine control module (ECM) #A35 for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.





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.
- Ignition on.
Select Volvo Scan Tool (ST) to read off the outside temperature.

Note! If the radiator is hot the outside temperature sensor will heat up if the car is stationary.





Is the outside temperature value within bounds?

Yes - VERIFIED

No - 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 the signal cable

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