Note. For circuit reference, see DTC P0336 schematic.
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 (by-pass 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). An open in IC circuit, or a short to voltage in bypass circuit will set DTC 1350.