What it means
A fault is detected on the secondary (high-voltage) side of ignition coil L. The spark delivered to the plug is missing or too weak, causing a misfire on the cylinder served by coil L. Causes: a worn spark plug or wide gap, a cracked coil or boot, carbon tracking, or an open or leaking secondary winding.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Ignition coil L produces the high voltage that travels through its boot and spark plug to ignite the mixture in its cylinder. The controller sets this code when it detects a fault in that secondary spark path, such as a weak or missing spark from coil L.
Common causes
Most likely first.
- Spark plug worn or fouled
- Secondary breakdown inside coil L
Symptoms
- Check-engine light
- Engine misfire or rough running
- Hesitation or reduced power
How to diagnose it
- Record freeze-frame data and check misfire counts for the cylinder served by coil L to confirm the affected cylinder and operating conditions.
- With the engine off, inspect coil L and its boot for cracks, carbon tracks, moisture, oil, or burn marks.
- Remove and inspect the coil L spark plug for fouling, wear, and excessive gap; compare the gap with the manufacturer's specification.
- Check that the boot is seated firmly and that the plug well and secondary connections show no evidence of arcing or leakage.
- If the cause is not visible, test coil L's secondary winding and insulation using the manufacturer's procedure and specifications.
Common fixes
- Replace the worn or fouled spark plug served by coil L.
- Clean or replace a damaged or carbon-tracked coil L boot.
- Replace coil L if its secondary winding or insulation fails testing.
- Repair a damaged secondary connection or wiring found during inspection.
Can I keep driving?
Avoid hard acceleration and unnecessary driving while the coil L cylinder misfires because unburned fuel can overheat the catalytic converter. If the check-engine light flashes or the engine runs very rough, stop and arrange repair.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.