Test Description
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers on the diagnostic table.
- This step determines if the scan tool is receiving power through the DLC connector.
- The MIL should illuminate whenever the ignition is ON and the engine is not running.
- This step determines if the PCM is transmitting Class 2 serial data to the DLC and that the Class 2 data circuit is not open or shorted.
- This step determines if a DTC is current or stored in history.