Diagnostic Test

ACTIVE DTC
NOTE:
Diagnose any CAN - C Communication DTCs in the PCM or Ambient Air Temperature Sensor DTCs in the BCM before continuing.
1. 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 may result in possible serious or fatal injury.
  
  NOTE:
  Diagnose and repair any system voltage DTCs before continuing with this test.
2. With the scan tool, select View DTCs.
  Is the DTC Active at this time?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
AAT SENSOR
1. Turn the ignition off.
2. Disconnect the Ambient Air Temperature Sensor harness connector.
3. Ignition on, engine not running.
4. With the scan tool, read AAT Sensor voltage.
5. Connect a jumper wire between the AAT Sensor Signal circuit and the AAT Sensor Return circuit in the AAT Sensor harness connector.
  NOTE:
  The sensor voltage should be approximately 0.0 volts (plus or minus 0.1 volt) with the jumper wire in place.
  
  Does the scan tool display the voltage as described above?
  
  Yes
  - Verify that there is good pin to terminal contact in the Sensor and Control Module connectors. Replace the Ambient Air Temperature Sensor if no problems were found with the connectors.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
    NOTE:
    Remove the jumper wire before continuing.
AAT SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the BCM harness connector.
3. Ignition on, engine not running.
4. Measure the voltage on the AAT Sensor Signal circuit in the AAT Sensor harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the AAT Sensor Signal circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
AAT SENSOR SIGNAL CIRCUIT OPEN
1. Turn the ignition off.
2. Measure the resistance of the AAT Sensor Signal circuit from the AAT Sensor harness connector to the BCM harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the open in the AAT Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
AAT SENSOR RETURN CIRCUIT OPEN
1. Measure the resistance of the AAT Sensor Return circuit from the AAT Sensor harness connector to the BCM harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the AAT Return circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
BODY CONTROL MODULE (BCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the AAT 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. Verify that there is good pin to terminal contact in the Sensor and Control Module connectors.
4. Perform any Technical Service Bulletins that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
    Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace and program the Body Control Module (BCM) in accordance with the Service Information. Refer to MODULE, BODY CONTROL, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .