Signal Too Low. Permanent Fault

Signal too low. Permanent fault

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.
- Reinstall components, reconnect connectors etc.
- Ignition on.
- Read off Intake Air Temperature (IAT) sensor signal.
Check that the signal is within its permitted range. The voltage can vary between 0.17 V and 4.9 V depending on air temperature. At 20 °C (68°F) voltage should be approximately 3.5 V.
If signal is now OK this indicates that the fault was caused by poor contact in the connector.

Other information
- To access/replace the Intake Air Temperature (IAT) sensor see Intake Air Temperature Sensor (IAT Sensor), replacing, B5234T9, B5244T7 Removal and Replacement.













Is the signal OK?

Yes - FAULT FOUND

No - Checking wiring and components

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Checking wiring and components
Check the Intake Air Temperature (IAT) sensor resistance.

Note! The Intake Air Temperature (IAT) sensor can be defective if the signal cable has been short-circuited to supply voltage. Check this before replacing the sensor.

Check signal cable between control module #A5 (#A5) and intake air temperature (IAT) sensor connector #1 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault and a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Hint: With the ignition on and intake air temperature (IAT) sensor connector disconnected voltage between #1 and ground terminal should be approximately 5 V.

Check the ground lead between control module #A60 (#A60) and intake air temperature (IAT) sensor connector #2 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault
Remedy as necessary.

Other information
- Connecting the breakout box/accessing the control module, see Connecting the breakout box, B5234T9, B5244T7 Connecting The Breakout Box.
- To access/replace the Intake Air Temperature (IAT) sensor see Intake Air Temperature Sensor (IAT Sensor), replacing, B5234T9, B5244T7 Removal and Replacement.
- For information about signals, see Signal specification Signal Specifications.














Continue - Verification

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Verification




Verification

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








- Ignition off.
- Reconnect the connectors, reinstall components etc.
- Ignition on.
- Read off Intake Air Temperature (IAT) sensor signal. The Intake Air Temperature (IAT) sensor is integrated into the Mass Air Flow (MAF) sensor.
Check that the signal is OK according to the table value:.





Is the signal OK?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFICATION FAILED - Fault-tracing information

VERIFIED - FAULT FOUND

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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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