C 2500 Suburban 2WD V8-5.7L VIN R (1996)
Idle Speed: Adjustments
Controlled Idle Speed
NOTE: There should be no Diagnostic Trouble Code (DTC)s 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 Data Link Connector (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 for controlled idle speed and Idle Air Control (IAC) valve pintle position (counts). Refer to Idle Air Control Valve /
Service and Repair. See: Idle Air Control (IAC) Valve/Service and Repair
8. If within specifications, the idle speed is being correctly controlled by the control module.
9. If not within specifications, refer to Driveability Symptoms. Refer to System Diagnosis for testing information. See: Computers and Control
Systems/Testing and Inspection