Ignition Control Module: Description and Operation
PURPOSEThe Ignition Control Module (ICM) assists the Powertrain Control Module (PCM), by operating the ignition coils and injectors 1 and 5. The ICM responds to commands from the PCM and controls ignition coil dwell and ignition timing.
OPERATION
The ICM receives vehicle speed input directly and transmits data to the PCM through the Multiplexer (MUX) circuit.
The ICM and PCM both receive crankshaft and camshaft position directly. The PCM supplies an 8 Volt referance signal to the crankshaft, camshaft position sensor, and ICM.