Diagnosis and Testing
- Verify the customer concern by operating the system.
- Visually inspect for obvious signs of mechanical or electrical damage.
- If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
- If the concern is not visually evident, refer to the Symptom Chart in the appropriate article.
DIAGNOSTIC TROUBLE CODES
| DTC | Possible Source | Action |
|---|---|---|
| P0300 Random misfire detected. P0301 to P0308 Misfire at cylinders 1 to 8 | Poor cylinder compression. Damaged or worn piston rings. Inlet/exhaust valve stuck open/closed. Worn camshaft. Damaged cylinder head gasket. Sparkplug fouled. | Mechanical check. |
| Fuel delivery pressure (high). Faulty injector (inoperative/leaking). Fuel injector continuously open. Fuel contamination. | Refer to FUEL CHARGING & CONTROLS - 4.0L | |
| Damaged ignition coil. Damaged associated electrical harness/connection. Damaged spark plug. | Repair or replace as necessary. | |
| P0351 Ignition coil A primary circuit malfunction | Ignition coil open/short circuit. Ignition coil insulation breakdown. Damaged harness. Connector pins bent or corroded. Damaged ignition circuit ground. Damaged PCM. | GO to PINPOINT TEST A for individual DTC. |
| P0352 Ignition coil B primary circuit malfunction | Ignition coil open/short circuit. Ignition coil insulation breakdown. Damaged harness. Connector pins bent or corroded. Damaged ignition circuit ground fault. Damaged PCM failure. | GO to PINPOINT TEST A for individual DTC. |
| P0353 Ignition coil C primary circuit malfunction | Ignition coil open/short circuit. Ignition coil insulation breakdown. Damaged harness. Connector pins bent or corroded. Damaged ignition circuit ground. Damaged PCM. | GO to PINPOINT TEST A for individual DTC. |
| P0354 Ignition coil D primary circuit malfunction | Ignition coil open/short circuit. Ignition coil insulation breakdown. Damaged harness. Connector pins bent or corroded. Damaged ignition circuit ground. Damaged PCM. | GO to PINPOINT TEST A for individual DTC. |
| P0355 Ignition coil E primary circuit malfunction | Ignition coil open/short circuit. Ignition coil insulation breakdown. Damaged harness. Connector pins bent or corroded. Damaged ignition circuit ground. Damaged PCM. | GO to PINPOINT TEST A for individual DTC. |
| P0356 Ignition coil F primary circuit malfunction | Ignition coil open/short circuit. Ignition coil insulation breakdown. Damaged Harness. Connector pins bent or corroded. Damaged Ignition circuit ground. Damaged PCM. | GO to PINPOINT TEST A for individual DTC. |
| DTC P0357 Ignition coil G primary circuit malfunction | Ignition coil open/short circuit. Ignition coil insulation breakdown. Damaged harness. Connector pins bent or corroded. Damaged ignition circuit ground. Damaged PCM. | GO to PINPOINT TEST A for individual DTC. |
| DTC P0358 Ignition coil H primary circuit malfunction | Ignition coil open/short circuit. Ignition coil insulation breakdown. Damaged harness. Connector pins bent or corroded. Damaged ignition circuit ground. Damaged PCM. | GO to PINPOINT TEST A for individual DTC. |
DIAGNOSTIC TROUBLE CODE INDEX
