Ignition

P0362 — Ignition Coil “L” Primary/Secondary Circuit Malfunction

Severity: medium Drive with care, to a shop

What P0362 means

The PCM monitors the control circuit of ignition coil “L”. It normally supplies power to the coil and switches the primary circuit off at the right moment, which induces the high voltage in the secondary winding that fires the spark plug. P0362 sets when the circuit signal is not what the PCM expects, due to an open, a short, a failing coil or a driver fault. Which cylinder coil “L” serves depends on the manufacturer, so check the wiring diagram for your engine.

Symptoms

  • Check engine light on
  • Misfire or rough running
  • Unstable idle
  • Reduced power
  • Hesitation on acceleration
  • Hard starting or stalling

Possible causes

  1. Failed ignition coil “L”
  2. Open or short in the coil wiring
  3. Corroded or loose coil connector
  4. Faulty coil driver in the PCM
  5. Worn or faulty spark plug affecting the secondary circuit
  6. Missing power or ground at the coil

How to diagnose

  1. Scan for codes and freeze-frame data, and look for related misfire codes (P030x).
  2. Use the wiring diagram to identify which cylinder coil “L” serves.
  3. Inspect the coil connector and harness for heat damage, corrosion and chafing.
  4. Check that cylinder's spark plug for gap, wear, fouling and insulator cracks.
  5. Swap the coil with a neighboring one and see whether the code or misfire follows.
  6. Check power, ground and the control signal at the coil connector with a multimeter or scope.
  7. Measure coil winding resistance against the manufacturer's spec.
  8. If the wiring and coil are good, test the PCM driver.

Common fixes

  • Replace ignition coil “L”
  • Replace the spark plugs as a set
  • Repair the wiring or replace the connector
  • Replace or reprogram the PCM if the driver has failed

Questions and answers

What does P0362 mean?

It means a fault in the primary or secondary circuit of ignition coil “L”. The coil, wiring or connector is the usual cause, and the PCM is a less common one.

Can I drive with P0362?

Only a short distance and gently, for example to a shop. Misfires can damage the catalytic converter, and you should avoid driving if the check engine light is flashing.

Is replacing the coil enough?

Not always. Check the spark plug, connector and wiring first, or the new coil may fail quickly.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.