P0072-AMBIENT AIR TEMPERATURE SENSOR CIRCUIT LOW
P0072-AMBIENT AIR TEMPERATURE SENSOR CIRCUIT LOW
For a complete wiring diagram, refer to the Wiring Information.
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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 Totally Integrated Power Module (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 |
| (G31) AAT SIGNAL CIRCUIT SHORTED TO THE (G931) AAT RETURN |
| AAT SENSOR |
| TOTALLY INTEGRATED POWER MODULE (TIPM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
1. AAT SENSOR VOLTAGE BELOW 0.078 OF A VOLT
| 1. | Ignition on, engine not running. |
| 2. | With a scan tool, read the AAT voltage. |
Is the voltage below 0.078 of a volt?
Yes
- Go To 2
No
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Perform the CHECKING FOR AN INTERMITTENT DTC diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM)
- Standard Procedure).
| 1. | Turn the ignition off. |
| 2. | Disconnect the AAT harness connector. |
| 3. | Ignition on, engine not running. |
| 4. | With a scan tool, read AAT voltage. |
Is the voltage above 1.0 volt?
Yes
- Replace the AAT Sensor.
- Perform the BODY VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).
No
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Go To 3
3. (G31) AAT SIGNAL CIRCUIT SHORTED TO THE (G931) AAT RETURN CIRCUIT
 |
| 1. | Turn the ignition off. |
| 2. | Disconnect the C4 TIPM harness connector. |
| 3. | 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
- Repair the short to between the (G931) AAT Return circuit and the (G31) AAT Signal circuit.
- Perform the BODY VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).
No
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Go To 4
4. (G31) AAT SIGNAL CIRCUIT SHORTED GROUND
 |
| 1. | Measure the resistance between ground and the (G31) AAT Signal circuit in the AAT Sensor harness connector. |
Is the resistance below 1000 ohms?
Yes
- Repair the short to ground in the (G31) AAT Signal circuit.
- Perform the BODY VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).
No
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Go To 5
5. TOTALLY INTEGRATED POWER MODULE (TIPM)
| NOTE: | Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary. |
| 1. | 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
- Repair as necessary.
- Perform the BODY VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).
No
- Replace and program the Totally Integrated Power Module in accordance with the Service Information.
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Perform the BODY VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM)
- Standard Procedure).