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 greater than 4.98 volts for more than 2.8 seconds. One Trip Fault. Three good trips to turn off the MIL.Possible Causes(G31) AAT SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE(G31) AAT SIGNAL CIRCUIT OPEN(G931) AAT RETURN CIRCUIT OPENAAT SENSORTIPMAlways perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).1. AAT SENSOR VOLTAGE ABOVE 4.98 VOLTSIgnition on, engine not running.With a scan tool, read the AAT voltage.Is the voltage above 4.98 volts?YesGo To 2 NoRefer 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 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?YesReplace the AAT Sensor.Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 3Remove the jumper wire before continuing.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?YesRepair the short to battery voltage in 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 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?YesGo To 5NoRepair the open in the (G31) AAT Signal circuit.Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)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?YesGo To 6NoRepair the open in the (G931) AAT Return circuit.Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)6. TIPM 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?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)