P0072-AMBIENT AIR TEMPERATURE SENSOR CIRCUIT LOW





For a complete wiring diagram Refer to Section 8W.


  • When Monitored:

    The ignition key on.

  • Set Condition:

    Ambient Temperature Sensor is less than 0.078 of a volt at the PCM for 2.8 seconds. One Trip Fault. Three good trips to turn off the MIL.


Possible Causes
 
(G31) AAT SIGNAL CIRCUIT SHORTED TO GROUND
 
(G31) AAT SIGNAL CIRCUIT SHORTED TO THE (G931) SENSOR GROUND CIRCUIT
 
AMBIENT AIR TEMPERATURE SENSOR
 
FRONT CONTROL MODULE
 


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



Diagnostic Test

1.AAT SENSOR VOLTAGE BELOW 0.078 OF A VOLT

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





Is the voltage below 0.078 of a volt?

Yes
  • Go To 2


No

2.CHECKING AAT SENSOR






Is the voltage above 4.6 volts?

Yes


No
  • Go To 3

3.(G31) AAT SIGNAL CIRCUIT SHORTED TO GROUND







Is the resistance below 100 ohms?

Yes


No
  • Go To 4

4.(G31) AAT SIGNAL CIRCUIT SHORTED TO THE (G931) SENSOR GROUND CIRCUIT





Is the resistance below 5.0 ohms?

Yes


No
  • Go To 5

5.FRONT CONTROL MODULE

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




Were there any problems found?

Yes


No