Ignition Control (IC) Timing Advance System
WARNING: This page is about a different car, the 1995 Oldsmobile Ninety-Eight and 1995 Buick Park Avenue. However, it is still accessible from the selected car via links, so may be relevant.
- A malfunction in the IC circuit (formerly referred to as the EST circuit) should set a related diagnostic trouble code. Start engine and warm to operating temperature. On vehicles equipped with a manual transmission, increase engine speed to about 2000 RPM. On vehicle equipped with an automatic transmission, slightly increase idle speed.
- Ground DLC "test" terminal "B" (not applicable to all models). A noticeable change in engine speed should occur. If no change occurs, see DIAGNOSTIC CIRCUIT CHECK in BASIC TESTING article in the ENGINE PERFORMANCE section.