Circuit Description
WARNING: This page is about a different car, the 1997 GMC Savana, 1997 Chevrolet Chevy Van, and 1997 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
While engine is warming, VCM monitors ECT sensor to determine the amount of time it takes engine to reach coolant temperature required for closed loop operation. Test will not be run if either intake air or engine coolant temperature are less than predetermined temperature. VCM will only run test on a cold start and only once per cold start.