Note. For connector terminal identification, see CONNECTOR IDENTIFICATION . For circuit identification and wiring diagram, see CHEROKEE wiring diagram in WIRING DIAGRAMS article.
Note. DTC P0351: IGNITION COIL #1 PRIMARY CIRCUIT is monitored with battery voltage more than 8 volts during engine cranking or more than 12 volts with engine running at less than 2016 (RPM), and no coils in dwell when checked. DTC may be stored in Powertrain Control Module (PCM) when PCM senses peak current is not achieved with battery based dwell plus 1.5 milliseconds of diagnostic offset. DTC P0351: IGNITION COIL #1 PRIMARY CIRCUIT takes less than 3 seconds to set with engine cranking, or up to 6 seconds with engine running. Possible causes are: defective ignition coil No. 1, defective PCM, defective connectors or defective wiring.
- Turn ignition on, with engine off. Using scan tool, read DTCs. If DTC SPECIFIC GOOD TRIP COUNTER is displayed and displayed count is "0", go to next step. If DTC SPECIFIC GOOD TRIP COUNTER is not displayed or displayed count is not "0", go to step 8).
- Turn ignition off. Disconnect ignition coil No. 1 connector. Clean and/or repair connector as necessary. Turn ignition on, with engine off. Using scan tool, actuate ignition coil No. 1. Connect one end of test light to ground. Touch other end of test light to ignition coil No. 1 connector, ASD relay output circuit (Dark Green/Orange wire). If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair ASD relay output circuit (Dark Green/Orange wire) for open or high resistance. Perform TEST VER-5A.
- Turn ignition off. Ensure ignition coil No. 1 connector is still disconnected. Visually inspect connector for corroded, damaged, pushed-out or miswired terminals. Repair connector as necessary. Perform TEST VER-5A. If connector is okay, go to next step.
- Turn ignition off. Ensure ignition coil No. 1 connector is still disconnected. Connect one end of test light to 12-volt source. Touch other end of test light to ignition coil No. 1 connector, driver circuit (Gray wire) while cranking engine. If test light does not blink or flicker, go to next step. If test light blinks or flickers, replace ignition coil No. 1. Perform TEST VER-5A.
- Ensure ignition is off. Ensure ignition coil No. 1 connector is still disconnected. Disconnect PCM connectors. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. Clean and/or repair connectors as necessary. Using an ohmmeter, check resistance between ground and ignition coil No. 1 connector, driver circuit (Gray wire). If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair driver circuit for short to ground. Perform TEST VER-5A.
- Ensure ignition is off. Ensure ignition coil No. 1 and PCM connectors are still disconnected. Using ohmmeter, check resistance of ignition coil No. 1, driver circuit (Gray wire) between ignition coil No. 1 and PCM. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in ignition coil No. 1 driver circuit. Perform TEST VER-5A.
- At this time, PCM is assumed to be defective. Replace PCM. Perform TEST VER-5A.
- Start engine and allow it to idle. With engine running, wiggle wiring harness from ignition coil No. 1 to PCM. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. Using scan tool, read DTCs. If DTC SPECIFIC GOOD TRIP COUNTER is displayed and displayed count is "0", and engine misses, repair wiring where wiggling caused engine to miss. Perform TEST VER-5A. If engine did not miss and DTC SPECIFIC GOOD TRIP COUNTER is not displayed or displayed count is not "0", go to next step.
- Turn ignition off. Visually inspect related connectors and wiring harness for damage. Repair connectors and wiring harness as necessary. Perform TEST VER-5A. If connectors and wiring harness are okay, test is complete.