P009A-INTAKE AIR TEMP/ AMBIENT AIR TEMP PLAUSIBILITY
For a complete wiring diagram Refer to Section 8W
| Possible Causes |
| AAT SENSOR - COLD |
| AAT SENSOR - HOT |
| CHECKING CONNECTORS |
| IAT SENSOR - COLD |
| IAT SENSOR - HOT |
| INTERMITTENT CONDITION |
Diagnostic Test
1. CHECKING CONNECTORS
Turn the ignition off.
Disconnect the IAT and AAT Sensor harness connectors.
Inspect both connectors for poor terminal contact, corrosion, damage or other problems.
Is there any evidence of connector problems?
Yes
- Repair or replace as necessary.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Go To2
2. IAT SENSOR - COLD
NOTE: Allow the engine to completely cool to ambient temperature.
Turn the ignition on.
With the scan tool, read and note the engine coolant temperature.
With the scan tool, read the Intake Air Temperature and compare it to the engine coolant temperature reading.
Are the readings within 7°C (13°F) of each other?
Yes
- Go To3
No
- Check the wiring and connectors associated with the IAT Sensor for corrosion, damage or other problems. Repair as necessary. If wiring and connectors are o.k., replace the Intake Air Temperature Sensor.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
3. AAT SENSOR - COLD
NOTE: Allow the engine to completely cool to ambient temperature.
With the scan tool, read and note the engine coolant temperature.
With the scan tool, read the Ambient Air Temperature and compare it to the engine coolant temperature reading.
Are the readings within 7°C (13°F) of each other?
Yes
- Go To4
No
- Check the wiring and connectors associated with the AAT Sensor for corrosion, damage or other problems. Repair as necessary. If wiring and connectors are o.k., replace the Ambient Air Temperature Sensor.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
4. IAT SENSOR - HOT
Start the engine and bring the engine to operating temperature (thermostat open).
Turn the engine off and wait 10 minutes to allow the engine temperature to stabilize.
With the scan tool, read and note the engine coolant temperature.
With the scan tool, read the Intake Air Temperature.
Are the readings within 7°C (13°F) of each other?
Yes
- Go To5
No
- Check the wiring and connectors associated with the IAT Sensor for corrosion, damage or other problems. Repair as necessary. If wiring and connectors are o.k., replace the Intake Air Temperature Sensor.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
5. AAT SENSOR - HOT
Start the engine and bring the engine to operating temperature (thermostat open).
With the scan tool, read the Ambient Air Temperature.
Is the Ambient Temperature Sensor reading correct outside temperature?
Yes
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Check the wiring and connectors associated with the AAT Sensor for corrosion, damage or other problems. Repair as necessary. If wiring and connectors are o.k., replace the Ambient Air Temperature Sensor.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).