Diagnostic Test

WARNING: This page is about a different car, the 2013 RAM 2500 HD and 2012 RAM Pickup. However, it is still accessible from the selected car via links, so may be relevant.

AMBIENT AIR TEMPERATURE
NOTE:
Diagnose any CAN - C Communication DTCs before continuing.
1. Turn the ignition off.
2. If possible, llow the vehicle to sit with the ignition off in an environment where the temperature is consistent and above - 64°C (-83°F) until the engine coolant temperature is equal to ambient temperature.
3. Turn the ignition on.
4. With a scan tool, compare the AAT, ECT, and IAT sensor values.
  Is the Ambient Air Temperature Sensor value within 15°C (59°F) of the other two sensor values?
  
  Yes
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to STANDARD PROCEDURE .
  No
  - Go To 2
CHECK THE (G31) AAT SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Ambient Air Temperature Sensor harness connector.
3. Disconnect the Body Control Module (BCM) C4 harness connector.
4. Measure the resistance of the (G31) AAT Signal circuit between the Ambient Air Temperature Sensor harness connector and the BCM C4 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 3
  No
  - Repair the (G31) AAT Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE (G931) AAT SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (G931) AAT Sensor Ground circuit between the Ambient Air Temperature Sensor harness connector and the BCM C4 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (G931) AAT Sensor Ground for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
AMBIENT AIR TEMPERATURE SENSOR
1. Turn the ignition off.
2. Reconnect the BCM C4 harness connector.
3. Connect a jumper between the (G931) AAT Sensor Ground circuit and the (G31) AAT Signal circuit at the Ambient Air Temperature Sensor harness connector.
4. Turn the ignition on.
5. With the scan tool, read the Ambient Air Temperature Sensor signal voltage.
  Is the voltage below 0.1 volts with the jumper in place?
  
  Yes
  - Replace the Ambient Air Temperature Sensor in accordance with the service information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 5
BODY CONTROL MODULE (BCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Ambient Air Temperature Sensor and the Body Control Module (BCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Perform any Technical Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Replace the Body Control Module in accordance with the service information.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .