P0314 Single Cylinder Misfire (Cylinder not Specified)
OBD-II Trouble Code Technical Description
Single Cylinder Misfire (Cylinder not Specified)
What does that mean?
This generic powertrain/engine diagnostic trouble code typically applies to most manufacturers since 1996.
Those manufacturers include but are not limited to GM, Ford, Dodge, Chrysler, Jeep, Hyundai, Kia, Mazda, Mitsubishi, Volvo and VW.
This code is focused on the relationship between the crankshaft position sensor (CKP), the camshaft position sensor (CMP) and the engine controller (ECM/PCM). The PCM monitors the relationship between these two sensors and compares them to an ideal reference stored in the PCM. If the variation exceeds a calibrated percentage, a fault code is stored. This can be either an electrical fault or a mechanical issue, depending upon the reason for the misfire and the vehicle manufacturer.
Troubleshooting steps may vary depending upon manufacturer and the type of crankshaft position sensor (CKP), camshaft position sensor (CMP) and their wire colors.
Symptoms
Symptoms of a P0314 engine code may include:
Causes
Typically, the causes for this code to set are:
Most Common Issues:
Least likely:
Diagnostic Steps and Repair Information
A good starting point is always to check for technical service bulletins (TSB) for your particular vehicle. Your issue may be a known issue with a known fix put out by the manufacturer and can save you time and money during diagnosis.
Next, note if there are any other diagnostic fault codes. If any of them are ignition system/fuel system related, diagnose them first. Misdiagnosis has been known to occur if a technician diagnoses this code before any ignition system / fuel system related codes have been thoroughly diagnosed and dismissed. Insure there are no intake or exhaust leaks. An intake leak, or vacuum leak, makes the engine run lean. An exhaust leak gives the impression of a lean running engine by the air/fuel ratio sensor/oxygen sensor (AFR/O2).
After that, clear all diagnostic trouble codes and see if the P0314 returns. If it does not, then the problem was intermittent or the P0314 was a memory code, that is it was something in the past.
If the code resets, that is comes right back the next time you start the vehicle or the very next road test, further inspection is required. Locate the CKP sensor and the CMP sensor on your particular vehicle. Once located, visually inspect the connectors and wiring. Look for scraping, rubbing, bare wires, burned spots or melted plastic. Pull the connectors apart and carefully inspect the terminals (the metal parts) inside the plastic connectors. See if they look burnt or corroded in place of the normal metal color you are probably used to seeing. You can get some electrical contact cleaner and a plastic bristle brush at any parts store if you need to clean the terminals. If this is not possible, find some rubbing alcohol and a toothbrush to clean them with, just make sure you do not put the toothbrush back in the bathroom! Afterwards let them air dry, get some dielectric silicone compound (same stuff they use for light bulb sockets) and put some where the terminals come into contact.
Clear the diagnostic trouble codes from memory again, and see if this code returns. If it does not, then the connections were most likely your problem.
If the code does return, remove the CKP sensor and the CMP sensor from the engine. Look at the end of the sensor where it comes close to the timing components / flex plate / flywheel on the engine. Note if there is any damage to it, where it may have been struck by any of those components. If it looks like it may have been struck / damaged, it will need to be replaced. At this point in time, it is a wise suggestion to replace it with one from the OEM, or dealer. On several occasions, techs have replaced a bad CKP sensor, only to find they must replace them again because the aftermarket sensor did not meet the voltage specifications that the PCM was looking for. With this code, relating to these two sensors, be more suspect of the CMP sensor, as the CKP sensor would tend to cause the engine to die. The CMP sensor could cause it to lose its ability to identify individual cylinders.
If the prior tests have passed and the code is still present, monitor the air/fuel ratio sensor/oxygen sensor (AFR/O2). If it continually indicates that the engine is running lean, locate any and all possibilities that could cause a lean running/misfiring engine. These include:
Again, it cannot be stressed enough that all other codes must be diagnosed prior to this one, as issues that cause other codes to set can also cause this one to set as well.
If the code still cannot be cleared, the only thing left that can be done is to seek assistance from a trained automotive drivability diagnostician.
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Let us fix your problem. You are most welcome our diagnosis experts have in most cases the knowledge and skills to find the cause of the error code p0314 and to solve the problems.
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"Delete Error Code Permanently, Disable DTC Error Code Function for p0314 in the ECU"
In extreme cases, we even have the option to permanently remove the specific DTC p0314 and disable the function of the specific error code in the ECU. All other fault code functions will then continue to work to protect the engine. This is different from clearing an error code with a diagnostic device. We have the option to permanently remove the function of the specific error code, so that it never comes back. Also emergency running that occurs on the specific error code can be solved in most cases.
Of course we prefer to first try to solve the cause of the error code, but sometimes the only solution is to permanently disable the DTC function of p0314.
