P0072-AMBIENT AIR TEMPERATURE SENSOR CIRCUIT LOW (TIPM)
For a complete wiring diagram Refer to Section 8W.
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When Monitored:
With the ignition on. Battery voltage greater than 10.4 volts.
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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
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(G31) AAT SIGNAL CIRCUIT SHORTED TO GROUND
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(G31) AAT SIGNAL CIRCUIT SHORTED TO THE (G931) AAT RETURN
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AAT SENSOR
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TIPM
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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
Ignition on, engine not running.
With a scan tool, read the AAT voltage.
Is the voltage below 0.078 of a volt?
Yes
No
2.
AAT SENSOR
Turn 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?
Yes
No
3.
(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?
Yes
No
4.
(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?
Yes
No
5.
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