Ignition Control Module: Testing and Inspection

TESTING PROCEDURE:

NOTE: While trouble shooting, always check the wiring, fuses and connectors for good condition and routing. Use the wiring diagrams found in CHASSIS ELECTRICAL DIAGRAMS to supplement your testing efforts.

Checking Supply At Ignition Coil:

1. Turn ignition ON.
2. Measure voltage between ignition coil terminal 15 (blue) and ground.

Reading: approx. 12 volts

If not, check wire and connectors from terminal 15 to suppressor relay (located on driver side fenderwell). Repair as needed. If wiring is O.K., check suppressor relay (see SUPPRESSOR RELAY).
3. Turn ignition OFF.
4. Disconnect the power stage connector.
IMPORTANT: Ignition must be OFF when connecting or disconnecting power stage connector.
5. Remove rubber boot from connector to uncover pins. Always test the pins from the back. Never test pins from the front, damage may occur.

Checking Terminals #1 And 4 At Power Stage:

6. Turn ignition ON.
7. Measure voltage between power stage terminal 1 and ground.

Reading: approx. 12 volts

If not, check wire and connectors from power stage terminal 1 to ignition coil terminal 1. Repair as needed. If no fault can be found, proceed with next steps.
8. Measure voltage between power stage terminal 4 and ground.

Reading: approx. 12 volts

If not, check wire and connectors from terminal 4 ignition switch. Repair as needed.
9. Turn ignition OFF.

Checking Pin 1 And 4:

10. Check ignition coil primary winding by connecting an ohmmeter between terminals 1 (red-white) and 4 (blue).

Reading: 0.6 - 0.9 ohm

Checking Coil:

11. If resistance is:
a. to low, replace ignition coil and retest.
b. to high, check resistance between coil terminals 1 and 15. Reading still to high, replace coil and retest. Reading correct, repair fault in wiring or connectors.

Checking Coil Primary Winding:

12. Check ignition coil secondary winding by connecting an ohmmeter between coil terminals 1 and high-voltage outlet.

Reading: 6.5 - 9.0 K ohms

13. If not, replace ignition coil and retest.

Checking Power Stage Ground:

14. Check power stage ground wire by connecting the ohmmeter between terminal 2 and ground.

Reading: 0 ohm

15. If not, repair fault in wiring or connectors.

Checking Pin 3 And 5:

16. Check that wire screen is properly connected to terminal 3.

Checking Terminal #5:

17. Disconnect leads from ignition coil terminal 1 (red-white) and 15 (blue).
18. Connect voltmeter between terminal 5 at power stage connector and ground.
19. Run starter motor.

Reading: approx. 2 volts

a. If reading is correct, turn ignition OFF, disconnect all test equipment and reconnect all connectors. Run starter motor, if no spark is available at ignition coil replace and retest with new power stage.
b. If reading is incorrect, power stage is missing the ECU signal. Check wiring from terminal 5 (gray) to ECU. Repair as needed. If no fault can be found, ECU or another input component is faulty. Check all components and replace as needed.
20. Turn ignition OFF
21. After testing, disconnect all test equipment, reconnect all connectors and place rubber boot back over connector to cover pins.