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P0278 is a diagnostic trouble code (DTC) for "Cylinder 6 Contribution/Balance Fault". 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.
The P0278 code represents an abnormal amount of voltage being detected in the vehicle’s fuel injector circuit.
The P0278 code is stored when the PCM detects an amount of voltage in the fuel injector circuit that is outside of the manufacturer’s specifications. This code only applies to V6 vehicles. Voltage variations that exceed 10% of the manufacturer’s specified voltage will cause the P0278 code to get stored in the PCM as well as the Check Engine light to turn on.
The main cause of the P0278 is actually wildlife. As the top of the engine tends to be quite warm, it attracts small animals looking for a heated place to rest in the winter. While enjoying the shelter provided by your vehicle, though, they often gnaw through the wiring in front of them.
Other reasons your PCM has stored a P0278 code include:
There are actually a number of different symptoms that may accompany this code, but each is fairly different from the other. The abnormal voltage in one of your vehicle’s fuel injectors will definitely lead to reduced performance. Trying to accelerate may still be possible, but it will probably be quite choppy. When your vehicle is idling, it could make a skipping sound. The vehicle may even vibrate. If you check the RPMs, you might notice that they don’t remain consistent even though your car is sitting idle. Some people have even reported that their engine misfired.
The mechanic will begin by checking scanning for the code and then assessing the transmission. They’ll go through each cylinder to look for signs that a wire or connector that has been compromised. If they don’t find any electrical issues that need to be repaired, the mechanic will move onto using an ohmmeter to test for a consistent power supply to the vehicle’s fuel injectors. Finally, they’ll clear the code and do a short test drive to see if P0278 returns or if the issue may be an intermittent problem.
This code could be stored because your PCM actually failed, meaning there’s nothing wrong with your fuel injectors or their voltage. However, please keep in mind that this is actually extremely rare. A mechanic should exhaust every other possibility before dedicating time and resources to replacing the PCM.
Your life isn’t in danger because your vehicle has a P0278 code, but you’ll still want to get it in front of a professional mechanic right away. If your engine backfires, the repairs necessary could be very expensive. Even a choppy acceleration is nothing you want to experience on a regular basis. Aside from how uncomfortable it is, you’re also going to lose a lot of money on how poor your fuel efficiency is.
Your mechanic will most likely do one of the following to get you back on the road:
If the mechanic finds that P0278 was caused by a critter, here are some tips for deterring squirrels from making your car their home. Hopefully, they’ll help prevent this problem in the future.
YourMechanic employs certified mobile mechanics who can not only help you with a P0278 code, but also meet you at your home or place of work. To get your quote and schedule an appointment, either call us at 1-800-701-6220 or complete this online form.