P0073

P0073-AMBIENT AIR TEMPERATURE SENSOR CIRCUIT HIGH





For a complete wiring diagram REFER to DIAGRAMS/ELECTRICAL


- When Monitored:
With the engine running and battery voltage greater than 10 volts.

- Set Condition:
The PCM detects that the 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

NOTE: Diagnose any CAN - C Communication DTCs before continuing with this test.


NOTE: Diagnose and repair any system voltage DTCs before continuing with this test.

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.

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 Air Temperature Sensor connector.
Disconnect the C4 Totally Integrated Power Module connector.
Turn the ignition on.
Measure the voltage of the (G31) AAT Signal circuit in the Ambient Air Temperature Sensor harness connector.
Is there any voltage present?

Yes


- Repair the short to voltage in the (G31) AAT Signal circuit.
- Perform the Body Verification Test Ver. 1Body Verification Test


No


- Go to 3


3. (G31) AAT SIGNAL CIRCUIT OPEN




Turn the ignition off.

NOTE: When checking circuits at the Totally Integrated Power Module, be careful not to damage or distort the connector terminals. Improper measurement technique could result in poor pin to terminal contact.

Measure the resistance of the (G31) AAT Signal circuit between the Ambient Air Temperature Sensor harness connector and the C4 Totally Integrated Power Module harness connector.
Is the resistance below 5.0 ohms?

Yes


- Go to 4


No


- Repair the open in the (G31) AAT Signal circuit.
- Perform the Body Verification Test Ver. 1Body Verification Test


4. (G931) AAT RETURN CIRCUIT OPEN





NOTE: When checking circuits at the Totally Integrated Power Module, be careful not to damage or distort the connector terminals. Improper measurement technique could result in poor pin to terminal contact.

Measure the resistance of the (G931) AAT Return circuit between the Ambient Air Temperature Sensor harness connector and the C4 Totally Integrated Power Module harness connector.
Is the resistance below 5.0 ohms?

Yes


- Go to 5


No


- Repair the open in the (G931) AAT Return circuit.
- Perform the Body Verification Test Ver. 1Body Verification Test


5. AMBIENT AIR TEMPERATURE SENSOR SIGNAL VOLTAGE




Turn the ignition off.
Connect the C4 Totally Integrated Power Module harness connector.
Connector a jumper wire between the (G31) AAT Signal circuit and the (G931) AAT Return circuit in the Ambient Air Temperature Sensor harness connector.
Turn the ignition on.
With the scan tool, read the Ambient Air Temperature Sensor signal voltage.

NOTE: The voltage should be approximately 0.0 volts with the jumper wire in place.

Is the voltage as described with the jumper wire in place?

Yes


- Go to 6


No


- Go to 7


6. AMBIENT AIR TEMPERATURE SENSOR
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Ambient Air Temperature Sensor and the Totally Integrated Power Module.
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
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.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes


- Repair as necessary.
- Perform the Body Verification Test Ver. 1Body Verification Test


No


- Replace the Ambient Air Temperature Sensor.
- Perform the Body Verification Test Ver. 1Body Verification Test


7. TOTALLY INTEGRATED POWER MODULE
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Ambient Air Temperature Sensor and the Totally Integrated Power Module.
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
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.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes


- Repair as necessary.
- Perform the Body Verification Test Ver. 1Body Verification Test


No


- Replace the Totally Integrated Power Module.
- Perform the Body Verification Test Ver. 1Body Verification Test