Ignition Coil D Primary Circuit Malfunction
The engine's computer detected a problem with ignition coil D's primary electrical circuit, similar to a broken wire preventing power from reaching a light switch. This stops the coil from firing properly, preventing spark at one cylinder.
The ECM monitors the primary coil circuit's voltage, resistance, and current draw during ignition events. It detects open circuits, shorts to ground, high resistance in the coil driver transistor, or excessive current draw indicating coil failure. When readings fall outside acceptable ranges, the fault is triggered.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Coil Primary Current | 6-8 amps during dwell | Below 2 amps or above 12 amps |
| Circuit Voltage Drop | Less than 0.5V under load | Greater than 2V or open circuit detected |
Code P1364 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P1364 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.