Diagnostic Tests

1) IAT SENSOR VOLTAGE BELOW 0.10 VOLTS
Turn the ignition on.

With the scan tool, read the IAT voltage.

Is the voltage below 0.10 volt?

Yes
1. Go To 2).
No
1. Refer to the INTERMITTENT CONDITION diagnostic procedure.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
2) IAT SENSOR INTERNAL FAILURE
Turn the ignition off.

Disconnect the IAT Sensor harness connector.

Turn the ignition on.

With the scan tool, read IAT voltage.

Is the voltage approximately 5 volts?

Yes
1. Replace the Inlet Air Temperature Sensor.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
No
1. Go To 3).
3) (K69) IAT SENSOR SIGNAL SHORTED TO GROUND

Fig 1: MEASURING RESISTANCE OF IAT SENSOR SIGNAL CIRCUIT
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the IAT Sensor harness connector.

Disconnect the PCM harness connector.

Measure the resistance of the (K69) IAT Sensor Signal circuit in the IAT Sensor harness connector to ground.

Is the resistance below 100 ohms?

Yes
1. Repair the short to ground (K69) Inlet Air Temperature Sensor Signal circuit.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
No
1. Go To 4).
4) (K69) IAT SENSOR SIGNAL SHORTED TO (K916) SENSOR GROUND CIRCUIT
Turn the ignition off.

Disconnect the IAT Sensor harness connector.

Disconnect the PCM harness connector.

Measure the resistance between the (K69) IAT Sensor Signal circuit and the (K916) IAT Sensor ground circuit in the IAT Sensor harness connector.

Is the resistance below 100 ohms?

Yes
1. Repair the short to the (K916) Inlet Air Temperature Sensor ground circuit in the (K69) Inlet Air Temperature Sensor Signal circuit.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
No
1. Go To 5).
5) PCM
NOTE: Before Continuing: Disconnect the PCM harness connector and check the related wiring terminals for corrosion, damage or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

If there are no possible causes remaining, view repair.

Repair
1. Replace and program the Powertrain Control Module in accordance with the Service Information. (Refer to STANDARD PROCEDURE - PCM/ECM/SKREEM PROGRAMMING) .
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .