Circuit Description
WARNING: This page is about a different car, the 1996 Cadillac Seville, 1996 Cadillac Eldorado, and 1996 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
IC module creates a 4X signal and a 24X signal that is used by the PCM for ignition and fuel control. In this test, PCM checks for 4X reference pulses being received without 24X reference pulses. When engine is running and PCM is receiving 4X pulses without 24X reference pulses and the 24X reference signal line is low for 4 seconds, DTC will set.