Error P0308 – how to fix?

Code definition P0308

Cylinder 8 Misfire Detection

What does the code P0308 mean

Fault code P0308 indicates that the powertrain control module (PCM) has detected a problem with the ignition of the fuel supplied to cylinder 8. This usually needs to happen several times before the fault code is stored and the Check Engine light illuminates.

What are the causes of the P0308 code?

• Some potential causes of fault code P0308 include
• Faulty ignition components such as spark plugs, ignition coils, spark plug wires, or distributors.
• Faulty parts of the fuel system, such as the fuel pressure regulator, fuel injectors or the EGR valve.
• High vacuum leak
• Faulty powertrain control module.

What are the symptoms of fault code P0308?

Some of the symptoms of fault code P0308 that may occur in the driver are

• Uneven idling
• Hesitation
• Loss of power
• The engine may die
• The engine cannot start
• Reduced fuel economy

How does the mechanic diagnose the code P0308?

The first thing the mechanic will do when diagnosing the P0308 code is to check the ignition system. If there is something visually wrong with the ignition system, e.g. something is disconnected or damaged, troubleshoot the problem prior to further diagnosis.

If there is no apparent problem with the ignition system, a mechanic will check each spark plug and wire with an ignition tester to make sure that each spark plugs. If any problems are found during this test, they must be resolved before further diagnosis.

If there are no problems with the ignition system, the mechanic’s next stop is the fuel system. A fuel pressure test will likely be run to make sure the fuel pressure regulator is working properly. Another likely test the mechanic will perform on the fuel system is to check the fuel injector data with an OBD-II scanner. Any problems with the fuel system should be repaired as soon as possible as fuel is dangerous. A vacuum test may also be run concurrently with the fuel pressure test to ensure that the engine produces a sufficient vacuum.

If there are no issues with either of the two systems above, the mechanic’s next step is to use a high-tech scan tool to test the powertrain control module for proper operation. Any defective parts found during this diagnosis will be replaced upon customer request.

The most common errors when diagnosing the code P0308

The most common error in diagnosing any type of misfire code is spark plug replacement or tuning. This procedure usually only has a 50/50 chance of fixing the problem if not properly diagnosed. While spark plug failure is one of the main causes of a misfire, it is very important to evaluate all aspects of the problem before replacing any parts to avoid wasting time and money.

How serious is the P0308 code?

The code P0308 is a serious problem. This code, which is stored in the vehicle’s powertrain control module, may prevent the engine from operating properly. In the daily life of many people it is important that their vehicle is working properly and is able to transport them from place to place. This type of fault code is one of those that can leave the driver at the side of the road. It’s a good idea to find the cause of the ignition and fix it as soon as possible.

What repairs can fix the code P0308?

The repairs that can fix the P0308 code include:

1. Replace all spark plugs and wires (and distributor cap and rotor, if applicable).
2. Replace the manifold
3. Replacing the ignition coil (s)
4. Replace the fuel pressure regulator
5. Repair large vacuum leak
6. Replace the fuel injectors
7. Replace the powertrain control module

Additional notes regarding code P0308

Various things can cause incorrect ignition. Therefore, check every possibility before replacing parts. Most of the time, a misdiagnosis will be the result of not taking the time to fully check and test every part of your system that has the problem.