Diesel Data: Automotive Repair

6 Checking Spark Control Circuitry


Perform No Start Test 5 before proceeding.

1. Turn ignition switch Off and disconnect diagnostic read-out tool.
2. Disconnect ignition coil wire at distributor cap, then place coil wire within 1/4 inch of a good ground.
3. Disconnect 60-way connector from SMEC and inspect terminal for damage, repairing connector terminals as necessary.
4. Connect a jumper wire between terminal No. 58 and ground.
5. Connect a remote starter switch between terminal No. 34 of 60-way connector and the battery negative terminal.
6. With remote starter switch a safe distance away from battery, turn ignition switch On.
7. Press and release remote starter switch several times while watching for spark at ignition coil.
8. If spark is satisfactory, replace the SMEC and perform Test 16.
9. If spark is unsatisfactory, turn the ignition switch Off.
10. With SMEC 60-way connector still disconnected, disconnect SMEC 14-way connector.
11. Inspect terminals for damage, repairing as necessary.
12. Using an ohmmeter, connect one lead to terminal No. 34 of 60-way connector and the other lead to terminal No. 13 of 14-way connector.
13. If ohmmeter shows continuity, replace the SMEC and perform Test 16.
14. If ohmmeter shows no continuity, repair open in yellow wire between terminal No. 13 of 14-way connector and terminal No. 34 of 60-way connector, then perform Test 16.