Ignition Control Module: Testing and Inspection

Note: - See "Computers and Control Systems" when the MIL blinks.
- Perform an input test for the ignition control module (ICM) after finishing the fundamental tests for the ignition system and emissions systems.
- The tachometer should operate normally if the ICM is OK.


1. Remove the distributor cap, the distributor rotor, and the leak cover.

Ignition Control Module (ICM) Input Test:

2. Disconnect the wires from the ICM.
3. Turn the ignition switch ON and check for battery voltage between the BLK/YEL wire and body ground. If there is no battery voltage, check the BLK/YEL wire between the ignition switch and the ICM. If there is battery voltage, proceed to step 4.
4. Turn the ignition switch ON and check for battery voltage between the BLU2 wire and body ground. If there is no battery voltage check for proper operation of the ignition coil or for an open in the BLU2 wire between the ignition coil and the ICM. If there is battery voltage proceed to step 5.
5. Check the YEL/GRN wire between the ECM and the ICM.
6. Check the BLU1 wire between the tachometer and the ICM.
7. If all tests are normal, replace the ICM.