Operation CHARM: Car repair manuals for everyone.

Ignition Control Module: Testing and Inspection

NOTE: If the Malfunction Indicator Lamp (MIL) blinks, see appropriate Diagnostic Trouble Code chart in Computers and Control Systems before testing the coil.

- Perform an input test for the Ignition Control Module (ICM) after finishing the fundamental tests for the ignition system and the fuel and emissions systems.
- The tachometer should operate normally.

Distributor Components:






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


Ignition Control Module:






2. Disconnect the BLK/YEL, WHT/BLU, YEL/GRN, and BLU wires from the ICM.
3. Turn the ignition switch ON. Check for voltage between the BLK/YEL wire and body ground. There should be battery voltage.
- If there is no battery voltage, check the BLK/YEL wire between the ignition switch and the ICM.
- If there is battery voltage, go to step 4.

4. Turn the ignition switch ON. Check for voltage between the WHT/BLU wire and body ground. There should be battery voltage.
- If there is no battery voltage, check:
- Ignition coil.
- WHT/BLU wire between the ignition coil and the ICM.

- If there is battery voltage, go to step 5.

5. Check the YEL/GRN wire between the ECM and the ICM.
6. Check the BLU wire between the tachometer and the ICM.

7. If all tests are normal, replace the ICM.