HomeTrouble CodesP0362

P0362 — Ignition Coil L Primary Control Circuitopen

Generic OBD-II · all makesPowertrain (engine & transmission)

P0362 means the powertrain control module has detected an open circuit in the primary (low-voltage) control side of ignition coil 'L', so it cannot reliably fire that coil. An open can exist in the coil winding, the control wire, or the connector between the coil and the module. The result is typically a misfire on the cylinder served by that coil.

Symptoms

What causes it — most likely first

1. Faulty ignition coil

The coil's internal primary winding or driver connection can fail open, making this the single most common cause of a primary control circuit open code.

2. Open or damaged control circuit wiring

A break, pinch, abrasion, or rodent damage in the low-voltage control wire between the coil and the PCM creates the open the code reports.

3. Corroded or loose coil connector

Terminal spread, corrosion, or poor pin contact at the coil harness connector interrupts the primary control signal without damaging the coil itself.

4. Power or ground supply fault to coil

If the coil lacks battery voltage or a solid ground, the primary circuit cannot operate; this may be caused by a blown fuse, bad relay, or ground connection.

5. PCM coil driver failure

Although possible, a failed driver inside the PCM is uncommon for this code and should only be considered after the coil, wiring, connectors, and power/ground have been verified.

How it's diagnosed

  1. Visually inspect the ignition coil, connector, and nearby harness for damage, corrosion, oil contamination, or burned terminals
  2. Test the coil primary resistance and, when practical, swap it with a known-good coil to see if the code follows the suspect coil
  3. With the key on, verify battery voltage and ground are present at the coil connector using a digital multimeter or test lamp
  4. Check continuity and integrity of the coil primary control wire from the coil connector back to the PCM, and wiggle the harness to find intermittent opens
  5. If the coil, power, ground, and wiring are all good, use a scope or scan-tool cylinder output test to determine whether the PCM coil driver is switching properly

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationSAE generic — identical on every make

Frequently asked

Is it safe to keep driving with P0362?

It is best to drive only minimally. A steady misfire can overheat and damage the catalytic converter, and unburned fuel can enter the exhaust.

Do I need to replace the PCM for P0362?

Usually no. The failed component is most often the ignition coil, a connector, or wiring. PCM driver failure is genuinely rare for this code and should be confirmed by testing, not assumed.

What does the 'L' stand for in ignition coil L?

It is the manufacturer-specific designation for a particular ignition coil or cylinder position in the firing order. The exact cylinder varies by engine design, so consult the service information for your vehicle.

Can I just clear the code and see if it comes back?

You can clear it to verify whether the fault is continuous, but if the open still exists the code and misfire will return, and clearing it will not fix the underlying problem.