Ignition Control Module (ICM)
The ICM is a solid state ignition circuit with coil attached. The coil can be removed and serviced separately. The ECU signals ICM, which advances or retards ignition timing to meet various engine load requirements.
The ICM has only 2 output leads and one input lead. Electrical feed to ICM is through Terminal "A" of connector No. 1. See Fig 1. Terminal "B" of connector No. 1 is grounded at engine along with ECU and oxygen sensor ground wire.
To avoid potential electrical interference in various ECU circuitry, tachometer output signal wire is routed to diagnostic connector through a short section of ECU, engine and instrument panel harnesses.
The sole function of distributor is to transmit high voltage charge to correct spark plug in firing sequence. See Fig 2.