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.
- With the scan tool, read Body Control Module (BCM) DTCs and record on the repair order.
- Record the Environmental Data and any DTCs.
- With the scan tool, erase DTCs.
- Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
- 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 (G31) AAT SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
- Turn the ignition off.
- Disconnect the Ambient Air Temperature Sensor harness connector.
- Turn the ignition on.
- Measure the voltage on the (G31) AAT Sensor Signal circuit at the Ambient Air Temperature Sensor harness connector.
Is the voltage above 5.2 volts?
Yes
- Repair the short to voltage in the (G31) AAT Sensor Signal circuit.
- Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
No
- Go To 3
- 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.
- Turn the ignition off.
- Connect a jumper wire between the (G31) AAT Sensor Signal circuit and the (G931) Sensor Ground circuit at the Ambient Air Temperature Sensor harness connector.
- Turn the ignition on.
- With the scan tool, read the BCM DTCs.
Does the scan tool display DTC: P0070-11-AMBIENT AIR TEMPERATURE SENSOR CIRCUIT - CIRCUIT SHORT TO GROUND as active?
Yes
- 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 .
No
- Go to 4
- CHECK THE (G31) AAT SENSOR SIGNAL CIRCUIT FOR AN OPEN
- Turn the ignition off.
- Disconnect the BCM C4/D harness connector.
- Measure the resistance of the (G31) AAT Sensor Signal circuit between the Ambient Air Temperature Sensor harness connector and the BCM C4/D harness connector.
Is the resistance above 3.0 Ohms?
Yes
- Repair the open in the (G31) AAT Sensor Signal circuit.
- Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
No
- Go To 5
- CHECK THE (G931) SENSOR GROUND CIRCUIT FOR AN OPEN
- Measure the resistance of the (G931) Sensor Ground circuit between the Ambient Air Temperature Sensor harness connector and the BCM C4/D harness connector.
Is the resistance above 3.0 Ohms?
Yes
- Repair the open in the (G931) Sensor Ground circuit.
- Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
No
- Go To 6
- Measure the resistance of the (G931) Sensor Ground circuit between the Ambient Air Temperature Sensor harness connector and the BCM C4/D harness connector.
- CHECK RELATED HARNESS CONNECTIONS
- Disconnect all BCM harness connectors.
- Disconnect all related in-line harness connections (if equipped).
- Disconnect the related component harness connectors.
- 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.
- Reconnect all BCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
- Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
- Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
- With the scan tool, erase DTCs.
- Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
- 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.