2000 - 2999: 2670

2670-INTAKE AIR TEMPERATURE/AMBIENT AIR TEMPERATURE CORRELATION





For a complete wiring diagram Refer to the Wiring Information Electrical Diagrams






1. CHECKING CONNECTORS
1. Turn the ignition off.
2. Disconnect the MAF and AAT Sensor harness connectors.
3. 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 TestVerification Tests.

No

- Go To 2

2. MAF SENSOR - COLD

NOTE: Allow the engine to completely cool to ambient temperature.

1. Reconnect all connectors.
2. Turn the ignition on.
3. With the scan tool, read and note the engine coolant temperature.
4. 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 To 3

No

- Check the wiring and connectors associated with the MAF Sensor for corrosion, damage or other problems. Repair as necessary. If wiring and connectors are o.k., replace the Mass Air Flow Sensor.
- Perform the ECM Verification TestVerification Tests.

3. AAT SENSOR - COLD

NOTE: Allow the engine to completely cool to ambient temperature.

1. With the scan tool, read and note the engine coolant temperature.
2. 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 To 4

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 TestVerification Tests.

4. MAF SENSOR - HOT
1. Start the engine and bring the engine to operating temperature (thermostat open).
2. Turn the engine off and wait 10 minutes to allow the engine temperature to stabilize.
3. With the scan tool, read and note the engine coolant temperature.
4. With the scan tool, read the Intake Air Temperature.

Are the readings within 7°C (13°F) of each other?

Yes

- Go To 5

No

- Check the wiring and connectors associated with the MAF Sensor for corrosion, damage or other problems. Repair as necessary. If wiring and connectors are o.k., replace the Mass Air Flow Sensor.
- Perform the ECM Verification TestVerification Tests.

5. AAT SENSOR - HOT
1. Start the engine and bring the engine to operating temperature (thermostat open).
2. 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.

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 TestVerification Tests.