For a complete wiring diagram Refer to Section 8W.When Monitored:With the ignition on. Battery voltage greater than 10.4 volts.Set Condition:The Ambient Air Temperature (AAT) sensor circuit voltage at the TIPM is less than 0.078 of a volt for more than 2.8 seconds. One Trip Fault. Three good trips to clear the MIL.Possible Causes(G31) AAT SIGNAL CIRCUIT SHORTED TO GROUND(G31) AAT SIGNAL CIRCUIT SHORTED TO THE (G931) AAT RETURNAAT SENSORTIPMAlways perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).1. AAT SENSOR VOLTAGE BELOW 0.078 OF A VOLTIgnition on, engine not running.With a scan tool, read the AAT voltage.Is the voltage below 0.078 of a volt?YesGo To 2NoRefer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)2. AAT SENSORTurn the ignition off.Disconnect the AAT harness connector.Ignition on, engine not running.With a scan tool, read AAT voltage.Is the voltage above 1.0 volt?YesReplace the AAT Sensor.Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 33. (G31) AAT SIGNAL CIRCUIT SHORTED TO THE (G931) AAT RETURN CIRCUIT

Turn the ignition off.Disconnect the C4 TIPM harness connector.Measure the resistance between the (G931) AAT Return circuit and the (G31) AAT Signal circuit in the AAT Sensor harness connector.Is the resistance below 1000 ohms?YesRepair the short to between the (G931) AAT Return circuit and the (G31) AAT Signal circuit.Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 44. (G31) AAT SIGNAL CIRCUIT SHORTED GROUND

Measure the resistance between ground and the (G31) AAT Signal circuit in the AAT Sensor harness connector.Is the resistance below 1000 ohms?YesRepair the short to ground in the (G31) AAT Signal circuit.Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 55. TIPMBefore 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?YesRepair as necessary.Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoReplace and program the Totally Integrated Power Module in accordance with the Service Information.Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)