There should be no DTCs displayed. The idle air control system has been checked.

1. Set the parking brake.
2. Block the drive wheels.
3. Connect a scan tool to the DLC connector with the tool in the open mode.
4. Start the engine.
5. Bring the engine to the normal operating temperature.
6. Check for the correct state of the Transmission Range (TR) switch position on the scan tool.
7. Check the specifications table for controlled idle speed and IAC valve pintle position (counts). Refer to Fuel Systems.
8. If within specifications, the idle speed is being correctly controlled by the control module.
9. If not within specifications, refer to Driveability Symptoms.