What does it mean?
This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to OBD-II equipped vehicles. Although generic, specific repair steps may vary by make/model.
The COP (coil-on-plug) ignition system is what’s used on most modern engines. There’s an individual coil for each cylinder that’s controlled by the PCM (powertrain control module).
It eliminates the need for spark plug wires by placing the coil right above the spark plug. Two wires are dedicated to each coil. One is a battery feed typically from the electrical distribution center. The other wire is the coil control circuit from the PCM. The PCM grounds/ungrounds this circuit to activate or deactivate the coil. The coil control circuit is monitored by the PCM for faults.
If an open or short circuit is detected in the #12 coil control circuit, a P0362 may set. Additionally, depending on the vehicle, the PCM may also shut down the fuel injector for that cylinder as well.
Symptoms
Symptoms of a P0362 DTC may include:
• MIL (malfunction indicator lamp) illumination
• Engine misfire may be present or intermittent
Causes
Potential causes of a P0362 code include:
• Short to voltage or ground on COP control circuit
• Open in COP control circuit
• Loose connection at coil or broken connector locks
• Faulty coil (COP)
• Defective powertrain control module
Possible Solutions
Is the engine currently misfiring? If not, the problem is likely intermittent. Try testing the wiring at coil #12 and along the wiring harness to the PCM. If manipulating the wiring causes a surface misfire, repair the wiring issue. Check for poor connection at the coil connector. Verify the harness isn’t improperly routed or rubbing against anything. Repair as needed.
If the engine is currently running poorly, stop the engine and disconnect the wiring connector from coil #12. Then start the engine and check for a driver signal at coil #12. Using an oscilloscope will give you a visual pattern to observe, but since most people don’t have access to one, there’s a simpler way. Use a voltmeter on the AC Hertz scale and see if there’s a Hz reading between 5-20, which indicates the driver is working. If there’s a Hertz signal, replace ignition coil #12. It’s likely bad. If you detect no frequency signal from the PCM on the ignition coil control circuit, indicating the PCM is not grounding/ungrounding the circuit (or if there’s no visible pattern on the oscilloscope if you have one), leave the coil disconnected and check DC voltage on the control circuit at the ignition coil connector. If there’s significant voltage on this wire, there’s a short somewhere. Find the short and repair it.
If there’s no voltage on the control circuit, turn off the ignition. Disconnect the PCM connector and check continuity of the driver circuit between the PCM and the coil. If there’s no continuity, repair the open circuit or short to ground in the circuit. If continuity is present, check resistance between ground and the ignition coil connector. There should be infinite resistance. If there isn’t, repair the short to ground in the coil control circuit.
NOTE: If the ignition coil driver signal wire isn’t open or shorted to voltage or ground and there’s no trigger signal to the coil, suspect a faulty PCM coil driver. Also keep in mind that if the PCM driver has failed, there may be a wiring problem that caused the PCM failure. It’s a good idea to perform the above verification after PCM replacement to check that there won’t be a repeat failure. If you find the engine isn’t misfiring, the coil is being triggered properly but P0362 keeps resetting, there’s the possibility that the PCM coil monitoring system is faulty.