Circuit Description

Ignition Control Module (ICM) sends signals that the PCM requires for fuel control and spark advance calculations. At the start of engine crank, the ICM control spark advance (by-ass mode). When the second 3X reference pulse is recognized by the PCM, PCM applies 5 volts to by-pass circuit, commanding ICM to switch spark advance to PCM control (IC mode).

If PCM detects a short to voltage in by-ass circuit, DTC will set. A short to ground in the IC circuit or by-pass circuit will cause both DTCs P1361 and P1362 to set. Engine will start and run in by-pass mode timing.

The following conditions will set DTC:

• Engine running.
• PCM detects a short to voltage in by-pass circuit.