Permanent Fault, Signal Too High

Permanent fault, signal too high

Checking connector




- Ignition off.
- Intake air temperature (IAT) sensor connector disconnected.
Check connector for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault.
Remedy as necessary.





Were any faults found?

Yes - Verification

No - Checking ground lead

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Checking ground lead
Connect an ohmmeter between intake air temperature (IAT) sensor connector terminal 2 (engine control module (ECM) side) and ground.









The ohmmeter should display approximately 0 ohms.

OK - Checking the signal cable

Not OK - Checking wiring and terminals

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Checking the signal cable








- Ignition on.
- Disconnect intake air temperature (IAT) sensor connector.
Connect an ohmmeter between intake air temperature (IAT) sensor connector terminal 1 (engine control module (ECM) side) and ground.
The voltmeter should read approximately 5 V.
1. more than 5 V
2. approximately 5 V
3. 0 V.









Then continue with one of the above alternatives:

1 - Checking wiring and terminals

2 - Defective intake air temperature (IAT) sensor

3 - Checking wiring and terminals

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Checking wiring and terminals
Check cable between intake air temperature (IAT) sensor connector terminal 1 (engine control module (ECM) side) and engine control module (ECM) terminal 48 for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault.
Remedy as necessary.













Continue - Verification

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Defective intake air temperature (IAT) sensor
Try a new intake air temperature (IAT) sensor according to Replacing the intake air temperature sensor Replacing The Intake Air Temperature Sensor.

Continue - Verification

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Checking wiring and terminals
Check cable between intake air temperature (IAT) sensor connector terminal 1 (engine control module (ECM) side) and engine control module (ECM) terminal 48 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault.
Check cable between intake air temperature (IAT) sensor connector terminal 2 (engine control module (ECM) side) and engine control module (ECM) terminal 79 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault.
Remedy as necessary.













Continue - Verification

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Verification








- Reconnect connectors, reinstall components.
- Connect the VCT 2000.
- Ignition on.
Read the parameter AIR TEMP.





Is this reading OK?

Yes - FAULT FOUND

No - No Fault Found 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 connector

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