Circuit Description

Ignition Control Module (ICM) sends signals that PCM requires for fuel control and spark advance calculations. At start of engine crank, ICM controls spark advance (bypass mode). When second 3X signal is recognized by PCM, it applies 5 volts to bypass circuit, commanding ICM to switch Ignition Control (IC) of spark advance to PCM (IC mode). A short in IC circuit, or an open or short ground in by-pass circuit will set DTC 1361.