Diagnostic Test
- READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN 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 DTCs in all Electronic Control Units (ECUs) and record on the repair order.
- With the scan tool, run a vehicle Scan Report, or record the Environmental Data related to the DTCs.
- With the scan tool, erase all DTCs.
- Turn the ignition off for a minimum of 10.0 seconds.
- Turn the ignition on.
- Using the recorded Environmental Data and the When Monitored Conditions above, operate the vehicle in the conditions that set the DTC.
- With the scan tool, read Body Control Module (BCM) DTCs.
Did the DTC return?
Yes
- Go To 2
No
- Perform the appropriate INTERMITTENT CONDITION diagnostic procedure. Refer to STANDARD PROCEDURE .
- DISCONNECT THE AMBIENT AIR TEMPERATURE HARNESS CONNECTOR AND CHECK THE (G31) AAT SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
- Turn the ignition off.
- Disconnect the component harness connector(s) for the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- Turn the ignition on.
- Using a DVOM, measure the voltage on the circuit being tested at the component harness connector.
NOTE:When probing a circuit at any harness connector, always use an appropriate probing tool to prevent any possible damage to the harness connector terminals.
Is the voltage above 5.2 volts?
Yes
- Repair the circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
No
- Go To 3
- CONNECT A FUSED JUMPER WIRE BETWEEN THE (G31) AAT SENSOR SIGNAL CIRCUIT AND (G931) SENSOR GROUND CIRCUIT - CHECK FOR ADDITIONAL DTCS 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 fused jumper wire between the circuits being tested at the component harness connector. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- Turn the ignition on.
- With the scan tool, read the BCM DTCs.
Is DTC: P0070-11-AMBIENT AIR TEMPERATURE SENSOR CIRCUIT - CIRCUIT SHORT TO GROUND 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
- DISCONNECT THE BCM HARNESS CONNECTOR(S) AND CHECK THE (G31) AAT SENSOR SIGNAL CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
- The ignition must be off when checking the resistance of a circuit.
- Disconnect all Electronic Control Unit (ECU) harness connectors containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note: The meter leads can add resistance to the measurement value.
- Connect one lead of the DVOM to the circuit being tested at the component harness connector.
- Connect the other lead to the circuit being tested at the ECU harness connector and measure the resistance of the circuit.
NOTE:When probing a circuit at any harness connector, always use an appropriate probing tool to prevent any possible damage to the harness connector terminals.
Is the resistance above 3.0 Ohms?
Yes
- Repair the circuit for an open or high resistance.
- Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
No
- Go To 5
- CHECK THE (G931) SENSOR GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
- The ignition must be off when checking the resistance of a circuit.
- Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note: The meter leads can add resistance to the measurement value.
- Connect one lead of the DVOM to the circuit being tested at the component harness connector.
- Connect the other lead to the circuit being tested at the ECU harness connector and measure the resistance of the circuit.
NOTE:When probing a circuit at any harness connector, always use an appropriate probing tool to prevent any possible damage to the harness connector terminals.
Is the resistance above 3.0 Ohms?
Yes
- Repair the circuit for an open or high resistance.
- Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
No
- Go To 6
- DISCONNECT RELATED MODULE HARNESS CONNECTIONS AND INSPECT FOR PROBLEMS
- 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.
- Connect all BCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
- Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
- Connect 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.