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P0355 is a diagnostic trouble code (DTC) for "Ignition Coil B Primary/Secondary Circuit Malfunction". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.
When the PCM (powertrain control module) identifies an electrical malfunction in ignition coil B’s primary or secondary circuit, it will set code P0355 to indicate the problem. The Check Engine Light will then illuminate.
The engine’s ignition coils’ job is to ignite the air/fuel mix in each of the engine’s combustion chambers. When one of these ignition coils (in this case, coil B) has an electrical problem, the engine will not be able to run smoothly, and it may hesitate or misfire.
The most common causes of the P0355 code include:
There may be a number of symptoms associated with a P0355 code, including:
After identifying the P0355 code and any other stored codes from the PCM, using an OBD-II scanner, the mechanic will start by visually inspecting the wiring and circuits connected to ignition coil B. They will then pay close attention to the crank signal, as a problem here can cause numerous other issues, including a P0355 code.
After testing any repairs up to this point, they will switch the coil and its spark plug with the coil and spark plug from a good cylinder. Then they’ll clear the code and go for a test drive. If the PCM records a code for the ignition coil in the new cylinder, the mechanic will know that the problem is either with the spark plug or the coil and will test each to see where the issue is originating from. Then they’ll take steps to resolve the code and retest it once more.
Sometimes the problem may actually be a leaking vacuum, rather than an issue with the ignition coil and/or spark plug. Replacing these without thoroughly inspecting the system can lead to an ineffective repair.
This code can significantly affect the drivability of the vehicle. If it’s left unresolved, it may also result in further engine damage and more expensive repairs down the road.
The most common repairs for a P0355 code are:
It’s very important that you get your P0355 code resolved and cleared as soon as possible. This kind of problem may have a quick and inexpensive fix, but it can result in major engine problems and/or very dangerous situations in the future. And, if you do not get the problem resolved, the Check Engine Light will remain illuminated, and the vehicle will be ineligible to pass an OBD-II emissions test when you need to register it to drive legally in your state.
YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.