P0073-AMBIENT AIR TEMPERATURE SENSOR CIRCUIT HIGH (TIPM)





For a complete wiring diagram Refer to Section 8W.



Possible Causes
(G31) AAT SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
(G31) AAT SIGNAL CIRCUIT OPEN
(G931) AAT RETURN CIRCUIT OPEN
AAT SENSOR
TIPM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).



Diagnostic Test

1. AAT SENSOR VOLTAGE ABOVE 4.98 VOLTS

Ignition on, engine not running.
With a scan tool, read the AAT voltage.

Is the voltage above 4.98 volts?

Yes


No

2. AAT SENSOR



Turn the ignition off.
Disconnect the AAT harness connector.
Connect a jumper wire between the (G31) AAT Signal circuit and the (G931) AAT Return circuit in the AAT harness connector.
Ignition on, engine not running.
With a scan tool, read AAT voltage.

Is the voltage below 1.0 volt with the jumper wire installed?

Yes


No

3. (G31) AAT SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE



Turn the ignition off.
Disconnect the C4 TIPM harness connector.
Ignition on, engine not running.
Measure the voltage on the (G31) AAT Signal circuit in the AAT Sensor harness connector.

Is voltage present?

Yes


No

4. (G31) AAT SIGNAL CIRCUIT OPEN



Turn the ignition off.
Measure the resistance of the (G31) AAT Signal circuit between the AAT Sensor harness connector and C4 TIPM harness connector.

Is the resistance below 10.0 ohms?

Yes


No

5. (G931) AAT RETURN CIRCUIT OPEN



Measure the resistance of the (G931) AAT Return circuit between the AAT Sensor harness connector and the C4 TIPM harness connector.

Is the resistance below 10.0 ohms?

Yes


No

6. TIPM

NOTE: Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.


Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Were there any problems found?

Yes


No