Ignition Coil L Primary/Secondary Circuit
The ignition coil for cylinder L isn't working properly—either the primary winding (which receives power) or secondary winding (which fires the spark plug) has failed. Think of it like a transformer that's broken and can't step up power to create a spark.
The ECU monitors primary circuit voltage and coil dwell time (how long current charges the coil), then checks for secondary spark confirmation via ion sensing or misfire detection. If voltage doesn't reach expected levels or spark fails to occur, the fault sets.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Primary Coil Voltage | 12V nominal when energized | Below 10V or erratic |
| Secondary Spark Confirmation | Spark detected each cycle | No spark or weak spark signal |
Code P0364 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, P0364 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.