P0363 OBD-II Trouble Code: Misfire Detected - Fueling Disabled

P0363 code definition

If the PCM has stored the P0363 code, it indicates that there has been a misfire in a cylinder, and that the PCM has disabled the fuel supply to the malfunctioning cylinder.

What the P0363 code means

There are several parts within the engine that inform the PCM of cylinder performance, including the crankshaft, the camshaft, and the engine’s general RPM. If the PCM detects that the camshaft or crankshaft positions have varied in an unusual manner, or if the engine RPM is not what it should be for the current conditions, the PCM will assume that a misfire has occurred within the cylinder related to the specific crankshaft and camshaft. The PCM then disables fuel supply to that cylinder, and stores the P0363 code.

What causes the P0363 code?

Cylinder misfire is often caused by the failure of an ignition system component. Failed spark plugs, ignition coils, and plug wires and boots could all be the root cause of the P0363 code.

Other causes for the P0363 code may include:

• Insufficient fuel pressure
• Engine vacuum leak
• Malfunctioning EGR system
• Faulty fuel injectors
• Clogged catalytic converter

What are the symptoms of the P0363 code?

If the PCM has stored the P0363 code, it is often preceded by a reduction of engine power, a very rough idle, or choppy acceleration. The Check Engine Lamp will be illuminated as well.

How does a mechanic diagnose the P0363 code?

All diagnostic procedures should begin with a thorough visual inspection of electrical components, such as wiring and connectors. If any are loose, corroded, faulty, open, or shorted, they should be replaced or repaired. The code should then be cleared, and the vehicle should be given a road test to see if the code is stored again. Often, recreating the failure and storage of the code is a good way to be sure of the exact issue. If the P0363 code returns, the mechanic will move on to other possible repairs.

Common mistakes when diagnosing the P0363 code

Most of the time, the P0363 code relates directly to the ignition system components. Because of this, these parts are frequently the first things to be repaired or replaced when addressing the P0363 code. However, there are several other factors that can play a part in the misfire of a cylinder, so any repair technician should be sure to give the system a thorough diagnosis.

How serious is the P0363 code?

The P0363 code represents a serious issue for the safe operation of the vehicle. Therefore, it should be addressed immediately. A misfiring cylinder could lead to other malfunctions that could result in engine failure.

What repairs can fix the P0363 code?

After diagnosing the P0363 code by scanning with an OBD-II scanner, performing an inspection of electrical components, and clearing the code to perform a retest, a mechanic has a few potential repairs to address the issue. These may include:

• Performing necessary tune-ups on ignition system components, including checking for faulty spark plugs, boots, ignition coils, distributor caps, and fuel filters.
• Moving coils, spark plugs, and other components to a cylinder that is operating properly, in order to assess which parts may be faulty.
• Checking the oxygen sensor data to determine if there is a vacuum leak, and repairing a broken, disconnected, or cracked vacuum hose if necessary.
• Inspecting and unclogging the catalytic converter.
• Repairing or replacing any faulty fuel injectors.

After any potential repair is performed, it’s important to clear the code and retest the vehicle, to determine if the repair fixed the issue.

Need help with a P0363 code?

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