Cadillac 19179581 Distributor Ignition Control Module Assembly

The HEI module functions as an electronic ON/OFF switch that regulates the current flow in the primary winding of the ignition coil, inducing a high voltage in the secondary winding, which is then directed through the rotor and secondary leads to ignite the spark plugs. To remove the module, first take off the distributor cap and rotor, then unscrew the module attaching screws and carefully lift the stamped sheet metal shield along with the module out of the distributor. Disconnect the leads from the module, ensuring to observe the color code to avoid interchanging them. If the same module is being replaced, do not wipe off the grease from the module base; however, if a new module is being installed, apply the included silicone grease to the metal face of the module and the distributor base for cooling purposes. For installation, connect the leads to the module while maintaining the color code, then secure the module and shield to the distributor with the screws, and finally reinstall the rotor and distributor cap.

The initial step is to disconnect the tachometer lead (if equipped) at the distributor and then check for a spark at the coil and spark plug wires.

The ICM is situated on the top of the rear camshaft cover.