P0073
Body Verification TestP0073-AMBIENT AIR TEMPERATURE SENSOR CIRCUIT HIGH
For a complete wiring diagram Consult Diagrams/Electrical
- When Monitored:
With the ignition on and battery voltage greater than 10.4 volts.
- Set Condition:
The PCM detects that the Ambient Temperature Sensor input voltage is above the maximum acceptable value.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.Initial Inspection and Diagnostic Overview
Diagnostic Test
1. DTC IS ACTIVE
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 can result in personal injury or death.
NOTE: Diagnose and repair any system voltage DTCs before continuing with this test.
With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go to 2
No
- REFER TO the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.Checking For An Intermittent DTC
2. (G31) AAT SIGNAL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the Ambient Temperature Sensor connector.
Disconnect the Body Control Module (BCM) connector.
Turn the ignition on.
Measure the voltage of the (G31) AAT Signal circuit in the Ambient Temperature Sensor harness connector.
Is there any voltage present?
Yes
- Repair the (G31) AAT Signal circuit for a short to voltage.
- Perform the Body Verification Test Ver. 1 Body Verification Test
No
- Go to 3
3. (G31) AAT SIGNAL OPEN OR HIGH RESISTANCE
Turn the ignition off.
CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.
Measure the resistance of the (G31) AAT Signal circuit between the Ambient Temperature Sensor harness connector and the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?
Yes
- Go to 4
No
- Repair the (G31) AAT Signal circuit for an open circuit or high resistance.
- Perform the Body Verification Test Ver. 1 Body Verification Test
4. (C918) SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE
CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.
Measure the resistance of the (C918) Sensor Ground circuit between the Ambient Temperature Sensor harness connector and the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?
Yes
- Go to 5
No
- Repair the (C918) Sensor Ground circuit for an open circuit or high resistance.
- Perform the Body Verification Test Ver. 1 Body Verification Test
5. AMBIENT TEMPERATURE SENSOR
Turn the ignition off.
Connect the Body Control Module (BCM) connector.
Connect a jumper wire between the (G31) AAT Signal circuit and the (C918) Sensor Ground in the Ambient Temperature Sensor harness connector.
Turn the ignition on.
With the scan tool, read the Ambient Temperature Sensor signal voltage.
NOTE: The sensor voltage should be approximately 0.0 volts (plus or minus.1 volt) with the jumper wire in place.
Does the scan tool display the voltage as described above?
Yes
- Replace the Ambient Temperature Sensor.
- Perform the Body Verification Test Ver. 1 Body Verification Test
No
- Go to 6
6. BODY CONTROL MODULE (BCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Ambient Temperature Sensor and the Body Control Module (BCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Search for any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the Body Verification Test Ver. 1 Body Verification Test
No
- Replace and program the Body Control Module (BCM).
- Perform the Body Verification Test Ver. 1 Body Verification Test