P0072-AMBIENT AIR TEMPERATURE SIGNAL VOLTAGE TOO LOW
For a complete wiring diagram Refer to Section 8W
- When Monitored:
With the ignition on.
- Set Condition:
The Ambient Air Temperature Sensor signal is below 0.20 volts.
| Possible Causes |
| (G31) AMBIENT AIR TEMP SENSOR SIGNAL CIRCUIT SHORTED TO GROUND |
| (G31) AMBIENT AIR TEMP SENSOR SIGNAL CIRCUIT SHORTED TO (G931) SENSOR GROUND |
| AMBIENT AIR TEMPERATURE SENSOR |
| TOTALLY INTEGRATED POWER MODULE |
Diagnostic Test
1. CHECK FOR ACTIVE DTCNOTE: If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the scan tool, erase TIPM DTCs.
Monitor the scan tool for TIPM DTCs for at least 2 minutes.
Did this DTC set again?
Yes
- Go To2
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
2. AMBIENT AIR TEMPERATURE SENSOR
Turn the ignition off.
Disconnect the Ambient Air Temperature Sensor harness connector.
Turn the ignition on.
Monitor the scan tool for TIPM DTCs for at least 2 minutes.
Does the scan tool display P0073 AMB AIR TEMP SENSOR SIGNAL VOLTAGE TOO HIGH?
Yes
- Replace the Ambient Air Temperature Sensor.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Go To3
3. (G31) AMBIENT AIR TEMP SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the TIPM harness connectors.
Measure the resistance between ground and the (G31) Ambient Air Temperature Sensor Signal circuit.
Is the resistance above 1000 ohms?
Yes
- Go To4
No
- Repair the (G31) Ambient Air Temperature Sensor Signal circuit for a short to ground.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
4. (G31) AMBIENT AIR TEMP SENSOR SIGNAL CIRCUIT SHORTED TO (G931) SENSOR GROUND
Turn the ignition off.
Measure the resistance between the (G31) Ambient Air Temperature Sensor Signal circuit and the (G931) Sensor Ground circuit.
Is the resistance above 1000 ohms?
Yes
- Replace and program the TIPM in accordance with the Service Information.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Repair the (G31) Ambient Air Temperature Sensor Signal circuit for a short to the (G931) Sensor Ground circuit.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).