Note. For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .
Circuit Description
Ignition system supplies 2 timing inputs to PCM, a high resolution signal (180 pulses/crankshaft revolution) and a low resolution signal (4 pulses/crankshaft revolution). PCM uses these signals to calculate spark timing. Timing signal is sent to ignition coil module on IC circuit. Each pulse on IC circuit triggers coil module to fire ignition coil. secondary ignition voltage then travels through distributor to spark plug. IC signal voltage ranges from about 0.5-4.5 volts.
DTC will set when following conditions are present
- PCM detects 84 crankshaft revolutions without any IC activity during cranking.