Note. For circuit reference, see WIRING DIAGRAMS article.
Circuit Description
Ignition Control (IC) module sends signals that the PCM requires for fuel control and spark advance calculations. At the start of engine crank, the IC module control spark advance (by-pass mode). When the second 3X reference pulse is recognized by PCM, PCM applies 5 volts to by-pass circuit, commanding IC module to switch spark advance to PCM control (IC mode).
If PCM detects a short to voltage in by-pass 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. DTC will set when engine is running and PCM detects a short to voltage in by-pass circuit.