P0363

What it means

P0363 is the generic code for a misfire being detected severe enough that the engine control unit has disabled fuelling to the affected cylinder or cylinders. It is set after the control unit sees sustained misfire from crankshaft speed variation and cuts the injectors to protect the catalytic converter from unburnt fuel. It is usually stored alongside specific cylinder misfire codes such as P0300 to P0308.

Symptoms

• Engine running rough or on fewer cylinders
• Noticeable loss of power and poor acceleration
• Flashing or illuminated engine warning light
• Juddering or shaking at idle and under load
• Smell of unburnt fuel from the exhaust
• Hesitation or difficulty starting

Possible causes

• Faulty spark plugs, ignition coils or coil connections on the cylinder that is misfiringlikely
• Faulty or blocked fuel injector, or a wiring fault to the injectorlikely
• Fuel delivery problem such as low fuel pressure, weak pump or contaminated fuelpossible
• Vacuum leak or intake leak causing a lean mixturepossible
• Low compression from worn rings, a burnt valve or a head gasket faultpossible
• Crankshaft position sensor or reluctor wheel fault causing false misfire detectionrare
• Valve timing fault or jumped timing belt or chainrare

How to diagnose

1. Read all stored codes and freeze frame data, noting which cylinders are affected, engine load, speed and temperature when the fault was set
2. Check for related codes such as cylinder-specific misfire, fuel trim, camshaft or crankshaft sensor codes
3. Inspect spark plugs, coils, connectors and wiring on the affected cylinders for damage, oil, moisture or wear
4. Swap a suspect coil or plug with another cylinder and see whether the misfire follows it
5. Check injector wiring, connectors and operation, and measure injector resistance or listen for injector clicking as per the manufacturer's data
6. Check fuel pressure and look at fuel trims for signs of a lean or rich condition, and inspect for vacuum leaks
7. Carry out a compression or cylinder leakage test if ignition and fuelling checks are all fine
8. Check crankshaft sensor signal and timing alignment if misfires appear on multiple cylinders at random

How to fix

• Replace worn spark plugs and any faulty ignition coils, using the specification for the engine
• Replace or professionally clean faulty injectors and repair damaged injector wiring or connectors
• Repair fuel supply faults such as a weak pump, blocked filter or regulator problem, and drain contaminated fuel
• Repair vacuum or intake leaks and replace perished hoses or gaskets
• Carry out the required mechanical repair for low compression, such as valve, ring or head gasket work
• Correct timing faults or replace a faulty crankshaft sensor, then clear the codes and retest

Can I keep driving?

Nearby codes

• P0362GenericIgnition Coil L Primary Control Circuit/Open
• P0364GenericDC/AC Converter Control Module Control Circuit Range/Performance