Diagnostic Test

CHECK FOR AN ACTIVE DTC
NOTE:
After repairing an Ambient Air Temperature (AAT) Sensor circuit, or replacing the AAT Sensor, the vehicle MUST be driven above 15 mph (24 km/h), for at least five minutes. Performing this allows the AAT Sensor data in the BCM to be updated. Failure to perform this may lead to the incorrect replacement of the BCM.
1. With the scan tool, read Body Control Module (BCM) DTCs and record on the repair order.
2. Record the Environmental Data and any DTCs.
3. With the scan tool, erase DTCs.
4. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
5. With the scan tool, read BCM DTCs.
  Did the DTC return?
  
  Yes
  - Go to 2
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE AMBIENT AIR TEMPERATURE SENSOR
NOTE:
The AAT Sensor operates between 345, 260 Ohms (low temperature) and 181 Ohms (high temperature).

At 20°C (68°F) the AAT Sensor resistance should be between 11, 370 Ohms and 13, 610 Ohms.
1. Turn the ignition off.
2. Disconnect the Ambient Air Temperature (AAT) Sensor harness connector.
3. Turn the ignition on.
4. With the scan tool, read BCM DTCs.
  Is the DTC Active?
  
  Yes
  - Go To 3
  No
  - Replace the Ambient Air Temperature Sensor in accordance with the Service Information. Refer to SENSOR, AMBIENT TEMPERATURE, REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (G31) AAT SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the BCM C6 harness connector.
3. Check the continuity between ground and the (G31) AAT Sensor Signal circuit at the Ambient Air Temperature Sensor harness connector.
  Is there continuity between ground and the (G31) AAT Sensor Signal circuit?
  
  Yes
  - Repair the short to ground in the (G31) AAT Sensor Signal circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 4
CHECK THE (G31) AAT SENSOR SIGNAL CIRCUIT FOR A SHORT TO THE (G931) SENSOR GROUND CIRCUIT
1. Check the continuity between the (G31) AAT Sensor Signal circuit and the (G931) Sensor Ground circuit at the Ambient Air Temperature Sensor harness connector.
  Is there continuity between the (G31) AAT Sensor Signal circuit and the (G931) Sensor Ground circuit?
  
  Yes
  - Repair the short between the (G31) AAT Sensor Signal circuit and the (G931) Sensor Ground circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go to 5
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all BCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
5. Reconnect all BCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read BCM DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Body Control Module (BCM) in accordance with the Service Information. Refer to MODULE, BODY CONTROL (BCM), REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  - Test complete.