Ignition System

Perform OBD system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article. After performing OBD system check, go to next step.
Disconnect 24X CKP sensor. Using scan tool, monitor 3X reference parameter while cranking engine. If 3X reference signal is present, go to next step. If 3X reference signal is not present, go to step 10 .
Reconnect 24X CKP sensor. Using spark tester, check for spark at each cylinder. If any cylinder does not indicate spark, go to next step. If all cylinders indicate spark, go to step 7 .
Check spark plugs, spark plug wires and ignition coils in question for short to ground or carbon tracking. Repair as necessary. If no problem is found, go to next step.
Measure resistance of spark plug wires in question. Resistance should be no greater than 600 ohms per foot. Repair as necessary. If resistance is okay, go to next step.
Switch ignition coil in question with known-good ignition coil. If fault follows affected ignition coil, replace ignition coil. If fault does not follow affected ignition coil, go to step 14 .
Check spark plug wires for proper routing and firing order. Repair as necessary. If no problem is found, go to next step.
Using DVOM, check spark plugs for internal short to ground. Repair as necessary. If spark plugs are okay, go to next step.
Remove spark plugs. Check for damage and replace as necessary.
Reconnect 24X CKP sensor. Disconnect 2-pin ignition control module harness connector. Turn ignition on. Using test light connected to ground, probe ignition control module ignition feed circuit at ignition control module harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 16 .
Connect test light between ignition control module ignition feed circuit and ignition control module ground circuit at ignition control module harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 19 .
Disconnect 7X CKP sensor harness connector from ignition control module. 7X CKP connector is 2-pin with Purple and Yellow wires. Using test light connected to battery positive terminal, probe 7X reference high circuit, and then 7X reference low circuit at harness connector. If test light illuminates for either circuit, go to step 17 . If test light does not illuminate for either circuit, go to next step.
Using test light connected to ground, probe 7X reference high circuit, and then 7X reference low circuit at harness connector. If test light illuminates for either circuit, go to step 18 . If test light does not illuminate for either circuit, go to next step.
Ensure battery voltage is within specification. Turn ignition off. Using DVOM set to AC duty cycle percent, connect leads between 7X reference high and low circuits at ignition control module harness connector. Monitor DVOM while cranking engine. If AC duty cycle is indicated, go to step 20 . If AC duty cycle is not indicated, go to next step.
Check 7X CKP sensor circuits for opens or short together. Repair as necessary. If circuits are okay, go to step 21 .
Repair open or short to ground in ignition control module ignition feed circuit.
Repair short to ground in 7X reference circuit which illuminated test light.
Repair short to voltage in 7X reference circuit which illuminated test light.
Repair open in ignition control module ground circuit.
Replace ignition control module.
Replace 7X CKP sensor.