Faulty Signal

Faulty signal

Checking the intake air temperature (IAT) sensor function




- Ignition on.
Read off the outside temperature in Volt. Check that it is correct according to the table values: Intake air temperature (IAT) sensor inlet Intake Air Temperature (IAT) Sensor Inlet.





Is the temperature reading OK?

Yes - Faulty signal. Intermittent fault

No - Checking connector

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Checking connector




- Ignition off.
- Check intake air temperature (IAT) sensor connector for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Other information:
- To access the Mass Air Flow (MAF) sensor, see the relevant service procedure.

Note! The Intake Air Temperature (IAT) sensor is integrated into the Mass Air Flow (MAF) sensor.






Continue - Checking intake air temperature (IAT) sensor

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Checking intake air temperature (IAT) sensor








- Reinstall components, reconnect connectors etc.
- Ignition on.
Read off the outside temperature in Volt. Check that it is correct according to the table values: Intake air temperature (IAT) sensor inlet Intake Air Temperature (IAT) Sensor Inlet.
If the temperature is now OK it means that the fault was caused by loose connections in the connector.

Other information:
- To access/replace the mass air flow (MAF) sensor, see

Note! The intake air temperature (IAT) sensor are integrated into the mass air flow (MAF) sensor and cannot be replaced separately.





Is the temperature reading OK?

Yes - Fault Found

No - Checking intake air temperature (IAT) sensor signal

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Checking intake air temperature (IAT) sensor signal
Check intake air temperature (IAT) sensor voltage. For table values, see Intake air temperature (IAT) sensor inlet Intake Air Temperature (IAT) Sensor Inlet.
Remedy as necessary.

Other information:
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box
- To access the control module, see
- To access/replace the Mass Air Flow (MAF) sensor, see
- For information about signals, see Signal specification Signal Description / Specification.






Continue - Verification

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Verification

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








- Ignition off.
- Reconnect connectors, reinstall components
- Ignition on.
Read off the temperature in Volts
Compare the measured value with the table value: Intake air temperature (IAT) sensor inlet Intake Air Temperature (IAT) Sensor Inlet

Other information:
- For information about signals, see Signal specification Signal Description / Specification.





Is the temperature reading OK?

Yes - Fault Found

No - FAULT-TRACING FAILED

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Faulty signal. Intermittent fault
Check mass air flow (MAF) sensor connector for intermittent contact resistance and oxidation according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
Remedy as necessary.

Other information:
- To access/replace the Mass Air Flow (MAF) sensor, see the relevant service procedure.
- For information about signals, see Signal specification Signal Description / Specification
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box
- To access the control module, see

Note! The manifold absolute pressure (MAP) sensor is integrated into the mass air flow (MAF) sensor and cannot be replaced separately.






Continue - DONE

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