Diagnostic Test

1) IAT SENSOR VOLTAGE BELOW 0.078 OF A VOLT
Ignition on, engine not running.

With a scan tool, read the IAT voltage.

Is the voltage below 0.078 of a volt?

Yes
1. Go To 2).
No
1. Refer to INTERMITTENT CONDITION .
2. Perform POWERTRAIN VERIFICATION TEST .
2) IAT SENSOR
Turn the ignition off.

Disconnect the IAT Sensor harness connector.

Ignition on, engine not running.

With a scan tool, read IAT voltage.

Is the voltage above 0.05 of a volt?

Yes
1. Replace the Intake Air Temperature Sensor.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To 3).
3) (K21) IAT SENSOR SIGNAL SHORTED TO GROUND

Fig 1: Checking Intake Air Temperature Sensor Signal Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the C2 PCM harness connector.

Measure the resistance between ground and the (K21) IAT Signal circuit in the IAT Sensor harness connector.

Is the resistance below 100 ohms?

Yes
1. Repair the short to ground in the (K21) IAT Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To 4).
4) (K21) IAT SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT

Fig 2: Checking IAT Signal Circuit Shorted To Sensor Ground
Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance between the (K21) IAT Signal circuit and the (K900) Sensor ground circuit in the IAT Sensor harness connector.

Is the resistance below 100 ohms?

Yes
1. Repair the short between the (K900) Sensor ground circuit and the (K21) IAT Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To 5).
5) PCM
NOTE: Before continuing, check the PCM harness connector 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.

Were there any problems found?

Yes
1. Repair as necessary.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Replace and program the Powertrain Control Module per Service Information.
2. Perform POWERTRAIN VERIFICATION TEST .