Ignition Control Module: Testing and Inspection

IGNITION CONTROL MODULE (ICM) / INPUT TEST

NOTE:
- Refer to How to Display and Read Diagnostic Trouble Codes if the malfunction indicator lamp (MIL) has been reported on.
- 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.

1. Remove the distributor ignition (DI) cap, the rotor, and the leak cover.
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 ICM.
- If there is battery voltage, go to step 5.

5. Disconnect the 32-P connector from the ECM, and check for continuity on the YEL/GRN wire between the ICM and ECM.
There should be continuity.

6. Check for continuity on the YEL/GRN wire to body ground.
There should be no continuity.

7. Reconnect the ECM 32-P connector.
8. Disconnect the gauge assembly 13-P connector, TCM 26-P connector, and cruise control 14-P connector.
9. Check for continuity on the BLU wire between the ICM and tachometer.
There should be continuity.

10. Check for continuity on the BLU wire to body ground.
There should be no continuity.

11. If all the tests are normal, reconnect the connectors, and replace the ICM.