Technical Description of OBD-II Trouble Code
Detection of Unauthorized Software/Calibration
What does that signify?
This is a generic diagnostic trouble code (DTC) that is applicable to many OBD-II vehicles (1996-newer). This includes vehicles from various manufacturers such as Acura, Audi, Buick, Cadillac, Chevrolet, Chrysler, Ford, Hyundai, Jaguar, Kia, Nissan, Scion, Toyota, etc. While the code is generic, the specific repair steps may vary depending on the year, make, model, and powertrain configuration of the vehicle.
A stored code P064F indicates that the powertrain control module (PCM) has detected an unauthorized or unrecognized software application or a controller calibration error.
The installation of factory software and calibration of on-board controllers is commonly referred to as programming. Although most programming is done before the vehicle is delivered to the owner, on-board controllers continue to adapt and learn to meet the specific needs of individual drivers and geographic locations. Factors such as voltage spikes, excessive temperatures, and excessive moisture can contribute to software and calibration failure.
Installing aftermarket software programs may result in a temporary code P064F being stored. Once the PCM learns the software and the code is cleared, it usually does not reoccur.
Every time the ignition is turned on and the PCM is energized, multiple controller self-tests are performed. These self-tests allow the PCM to monitor serial data carried over the controller area network (CAN) to ensure proper interfacing of on-board controllers. Memory functions and software applications are tested during this time and periodically when the ignition is in the ON position.
If a problem is detected in monitoring controller software/calibration, a code P064F will be stored and a malfunction indicator lamp (MIL) may illuminate.
A typical PCM powertrain control module, opened up:
What is the severity of this DTC?
A P064F should be considered severe as it can lead to various engine starting and/or drivability issues.
What are some of the symptoms of the code?
Symptoms of a P064F trouble code may include:
What are some of the common causes of the code?
Possible causes for this code may include:
What are some P064F troubleshooting steps?
Even for experienced technicians with advanced equipment, diagnosing a code P064F can be particularly challenging. Without access to reprogramming equipment, it is virtually impossible to make an accurate diagnosis.
Refer to your vehicle information source for technical service bulletins (TSB) that match the stored code, vehicle details (year, make, model, and engine), and exhibited symptoms. If you find the relevant TSB, it may provide helpful diagnostic information.
Start by connecting a scanner to the vehicle diagnostic port and retrieving all stored codes and freeze frame data. It is advisable to write down this information in case the code is intermittent.
After recording all relevant information, clear the codes and, if possible, test drive the vehicle until the code is reset or the PCM enters readiness mode.
If the PCM enters readiness mode, the code is intermittent and will be even more difficult to diagnose. The condition that caused the P064F to be stored may need to worsen before an accurate diagnosis can be made. On the other hand, if the code fails to reset and there are no drivability symptoms, the vehicle can be operated normally.
