OBD codes / P0362
P0362
SeriousIgnition Coil L Primary/Secondary Circuit (Cylinder 12)
Eleven healthy cylinders will carry the car so smoothly you may forget anything is wrong — but cylinder 12 is exhaling raw fuel into its bank's catalytic converter the entire time, and heat is what kills converters. Limit driving with a steady light; a flashing light means active damage, so make the repair immediate.
What this code means
P0362 is the last code in the coil-circuit family: an open or short detected in the primary or secondary circuit of ignition Coil L, the coil for cylinder 12. Only twelve-cylinder engines have a coil L, so this code lives exclusively on V12s and their variants. The ECM individually drives all twelve coils, switching each primary winding to command the spark and monitoring the circuit for the correct electrical response; when coil L's circuit fails that check, this code sets, usually with companion misfire code P0312 for cylinder 12. The fault is electrical by definition — a worn spark plug degrades spark quality but cannot open the circuit — so diagnosis centers on the coil, its connector, and its wiring. Cylinder 12 sits at the end of a bank, where harness runs terminate and connectors see heat and vibration; chafe points and corroded terminals are worth a careful look before condemning the coil. A blown coil fuse or a failed ECM driver are the remaining, less common possibilities.
Symptoms you might notice
- Misfire on cylinder 12 — easy to miss from the driver's seat on a V12
- Slight idle flutter or vibration under acceleration
- Check-engine light, flashing during active misfire
- Unburned-fuel smell from the exhaust
- Small power loss; companion code P0312 usually present
What it costs to fix
Typical range: $70–$500 · about ~0.3–2.5 hrs of labor
| If the cause is… | Part | Labor |
|---|---|---|
| Ignition coil (single) | $30–$150 | ~0.3–1.5 hrs |
| Wiring or connector repair | $5–$50 | ~0.5–2 hrs |
| Spark plugs (while in there) | $20–$100 | ~0.5–1.5 hrs |
As with the other V12 coil codes, the coil is a modest part and the money goes to access: engine covers, tight packaging, and end-of-bank location all add time, and V12-capable shops bill accordingly. Combining the repair with plugs and a look at the rest of that coil bank makes the most of the teardown.
The price swings on which cause it turns out to be — so confirm the cause before paying. Diagnose P0362 for my exact vehicle →
Frequently asked
Which vehicles can actually set P0362?
Only those with twelve-cylinder engines — coil L pairs with cylinder 12, which doesn't exist on anything smaller. Seeing P0362 reported on a four-, six-, or eight-cylinder car points to a scan error, not a real fault.
How do I know it's the coil and not the wiring or ECM?
Swap coil 12 with a neighboring cylinder's coil and clear the codes. Code follows the coil: replace the coil. Code stays on cylinder 12: inspect that cylinder's connector and harness leg for corrosion and chafe, and verify the coil fuse — only after all that checks out does the ECM driver become a suspect, and it's a rare one.
Is it safe to keep driving a V12 with P0362?
Mechanically the engine copes fine, but the misfire is steadily overheating one bank's catalytic converter — an especially costly part on these cars. With a steady check-engine light, keep trips short and gentle; with a flashing light, stop driving it until the circuit is repaired.
What's a realistic repair cost for P0362?
If it's the coil, the part itself is inexpensive — the cost is dominated by labor to get under the engine covers and by the shop's hourly rate. Wiring repairs cost little in materials but more in diagnosis. Either way it's a small bill next to the catalytic converter damage that prolonged misfiring can cause.
Seeing P0362 on your car? Get a diagnosis specific to your exact year, make and model.
Diagnose P0362 for my vehicleRelated trouble codes
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Generic OBD-II reference. Manufacturer-specific behavior varies — confirm with a scan tool and, for safety-related codes, a professional inspection.