Diagnostic Test

1) DTC IS ACTIVE
Start the engine and allow it to reach normal operating temperature.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

NOTE: Diagnose and repair any system voltage DTCs before continuing with this test.

With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes
1. Go to 2).
No
1. Refer to *CHECKING FOR AN INTERMITTENT DTC .
2) (G31) AAT SIGNAL CIRCUIT SHORTED TO GROUND

Fig 1: Checking Ambient Air Temperature Sensor Circuit
Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the Ambient Air Temperature Sensor connector.

Disconnect the Front Control Module (FCM) connector.

Measure the resistance between ground and the (G31) AAT Signal circuit in the Ambient Air Temperature Sensor harness connector.

Is the resistance above 100 ohms?

Yes
1. Go to 3).
No
1. Repair the (G31) AAT Signal circuit for a short to ground.
2. Perform BODY VERIFICATION TEST - VER 1 . (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES)
3) (G31) AAT SIGNAL CIRCUIT SHORTED TO (G931) SENSOR GROUND CIRCUIT

Fig 2: Checking Ambient Air Temperature Sensor Circuit
Courtesy of CHRYSLER LLC

Measure the resistance between the (G31) AAT Signal circuit and the (G931) Sensor Ground circuit in the Ambient Air Temperature Sensor harness connector.

Is the resistance above 100 ohms?

Yes
1. Go to 4).
No
1. Repair the (G31) AAT Signal circuit for a short to the (G931) Sensor Ground circuit.
2. Perform BODY VERIFICATION TEST - VER 1 .
4) (G31) AAT SIGNAL CIRCUIT OPEN CIRCUIT OR HIGH RESISTANCE

Fig 3: Checking Ambient Air Temperature Sensor Signal Circuit
Courtesy of CHRYSLER LLC

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

Measure the resistance of the (G31) AAT Signal circuit between the Ambient Air Temperature Sensor harness connector and the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes
1. Go to 5).
No
1. Repair the (G31) AAT Signal circuit for an open circuit or high resistance.
2. Perform BODY VERIFICATION TEST - VER 1 .
5) AMBIENT AIR TEMPERATURE SENSOR
Turn the ignition off.

Connect the Front Control Module (FCM) connector.

Turn the ignition on.

With the scan tool, read the Ambient Air Temperature Sensor signal voltage.

NOTE: The sensor voltage should be approximately 5.0 volts (plus or minus.1 volt) with the connector disconnected.

Does the scan tool display the voltage as described above?

Yes
1. Replace the Ambient Air Temperature Sensor in accordance with the service information.
2. Perform BODY VERIFICATION TEST - VER 1 .
No
1. Go to 6).
6) FRONT CONTROL MODULE (FCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Ambient Air Temperature Sensor and the Front Control Module (FCM).

Look for any chafed, pierced, pinched, or partially broken wires.

Look for broken, bent, pushed out or corroded terminals.

Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.

Look for the data to change or for the DTC to reset during the wiggle test.

Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes
1. Repair as necessary.
2. Perform BODY VERIFICATION TEST - VER 1 .
No
1. Replace and program the Front Control Module (FCM) in accordance with the Service Information.
2. Perform BODY VERIFICATION TEST - VER 1 .