P0362: Problem in the electrical circuit of ignition coil L, the coil for cylinder 12 on a V12 engine
Ignition coil L primary/secondary circuit malfunction
Severity: Severity not verified — if the car runs badly, have it inspected
The sources read give no severity guidance for this code. A timing or coil circuit fault can cause misfires or hard starting, so have it checked.
It gets more serious if:
- Inspect soon: Inspect soon if the engine misfires hard, the check engine light flashes, or the engine stalls or will not start.
P0362 in short
P0362 means the engine computer found a fault in the primary or secondary circuit of ignition coil L, which TroubleCodes.net ties to cylinder 12 on V12 engines. A failed coil, damaged wiring or, rarely, the computer is behind it. Expect a misfire on that cylinder.
The generic title is "Ignition coil L primary/secondary circuit malfunction". The computer watches the coil circuit and sets the code when it sees a fault.
TroubleCodes.net says the letter maps to cylinder 12 on V12 engines and that the code often appears with misfire code P0312. Engines with fewer cylinders will not normally use this code.
The listed causes are a faulty coil, wiring problems in the coil circuit, and the engine computer. Swapping the coil with another cylinder shows whether the fault follows the coil.
Most likely causes
These are general causes for this code across vehicles. None is specific to one make or model.
Cause 1: Failed ignition coil L
Common general cause- Why it ranks here
- TroubleCodes.net lists a faulty coil first for this code, and a coil swap is its first isolation test.
- What would change this
- Rises if the misfire moves to another cylinder when the coil is swapped. Falls if the misfire stays on the same cylinder.
Cause 2: Wiring or connector fault in the coil circuit
Common general cause- Why it ranks here
- The page lists wiring problems in the coil circuit; a corroded or damaged connector is the visible check.
- What would change this
- Rises if the connector is corroded or damaged, or continuity to the computer fails. Falls if the harness and connector test good.
Cause 3: Engine computer driver fault
Possible — needs testing- Why it ranks here
- Listed as a possible cause only. It is considered after the coil and wiring are cleared.
- What would change this
- Rises if the coil and wiring are good but the control signal is missing. Falls if the signal is present.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: Look over the coil and its connector for corrosion, damaged wires or a loose fit.
IfCorrosion or damage is visible
It meansRepair the connector or wiring.
IfEverything looks fine
It meansSwap the coil.
Step 2: Swap this coil with one from another cylinder, clear the codes and see where the misfire code appears.
Warning:Work only on a cool engine with the ignition off; the coil terminals carry very high voltage when running and V12 engines are tightly packed with hot parts.
IfThe misfire follows the coil
It meansThe coil has failed.
IfThe misfire stays on the same cylinder
It meansTest the coil wiring and computer signal.
Step 3: Check the coil has about 12 volts, check the computer's control signal with a test light while cranking, and check continuity to the computer.
Warning:Probing coil connectors while the engine cranks risks shorts and shock from ignition voltage, and can damage the computer. Have a shop do it.
IfPower or continuity is missing
It meansA wiring fault.
IfPower and wiring are good but the control signal is missing
It meansThe computer is suspect.
Symptoms
- Check engine light
- Misfire on cylinder 12
- Flashing check engine light with a hard misfire Gets more serious: stop and have it checked.
Compare with: Rough idle with the check engine light on, Car shaking with the check engine light on
How to fix
Step 1: Have the coil connector checked for corrosion or damage.
Step 2: Have the coil swapped with another cylinder's to see whether the fault follows it.
Parts and cost context
- Ignition coil:Test before replacing; prices and labour vary, so get a quote.
Labor varies by vehicle and shop; get a quote before you approve a repair.
Compare used part prices on PartPriceGuideOn your vehicle
We don't have reviewed vehicle-specific evidence for P0362 yet. The causes and tests above apply across vehicles.
Related codes
No curated relationships for P0362 yet.
Sources and review
- TroubleCodes.net generic code pages for P0361, P0362, P0370, P0371, P0372
- On-Board Diagnostic Trouble Codes (generic code title list)
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error