P06B8 Error of non-volatile random access memory (NVRAM) of the internal control module
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OBD-II Trouble Code - P06B8 - Data Sheet
P06B8 - Internal Control Module Non-Volatile Random Access Memory (NVRAM) Error
What does DTC P06b8 mean?
This Generic Powertrain Diagnostic Trouble Code (DTC) is commonly applied to many OBD-II vehicles. This may include but is not limited to Ford, Mazda, etc. vehicles.
When the P06B8 code persists, it means that the powertrain control module (PCM) has detected an internal nonvolatile memory access memory (NVRAM) processor performance error. Other controllers may also detect an internal PCM performance error (with NVRAM) and cause P06B8 to be saved.
The internal control module monitoring processors are responsible for the various controller self-testing functions and the overall accountability of the internal control module. NVRAM input and output signals are self-tested and continuously monitored by the PCM and other relevant controllers. The transmission control module (TCM), traction control module (TCSM), and other controllers also communicate with NVRAM.
In automotive applications, NVRAM is used to save data memory when the PCM is powered off. NVRAM is integrated into PCM. Although NVRAM is capable of over 1 million software changes and is designed to last for hundreds of years, it can be sensitive to excessive heat and humidity.
Whenever the ignition is turned on and the PCM is energized, the NVRAM self-test is initiated. In addition to performing a self test on the internal controller, the Controller Area Network (CAN) also compares the signals from each individual module to ensure that each controller is working as expected. These tests are performed at the same time.
If the PCM detects an internal mismatch in the NVRAM processor, a P06B8 code will be stored and a malfunction indicator lamp (MIL) may illuminate. In addition, if the PCM detects a problem between any of the on-board controllers that indicates an internal system error in the knock sensor, a P06B8 code will be stored and a malfunction indicator lamp (MIL) may illuminate. It may take several failure cycles to illuminate the MIL, depending on the perceived severity of the malfunction.
Example of PKM photo: 
What is the severity of this DTC?
Internal control module processor codes are to be classified as Severe. A stored P06B8 code can cause various handling problems.
What are some of the symptoms of a P06B8 code?
Symptoms of a P06B8 trouble code may include:
- Various symptoms of engine drivability
- Other Stored Diagnostic Trouble Codes
What are some of the common causes for the code?
Reasons for this code may include:
- Open or short circuit in the circuit or connectors in the CAN harness
- Insufficient grounding of the control module
- Damage or programming error in PCM
What are some steps to troubleshoot the P06B8?
Even for the most experienced and well-equipped professional technician, diagnosing the P06B8 code can be challenging. There is also the problem of reprogramming. Without the necessary reprogramming equipment, it will be impossible to replace the faulty controller and carry out a successful repair.
If there are ECM / PCM power supply codes, they obviously need to be corrected before attempting to diagnose P06B8.
There are some preliminary tests that can be performed before declaring a controller as faulty. You will need a diagnostic scanner, a digital volt-ohmmeter (DVOM) and a source of reliable information about the vehicle.
Connect the scanner to the vehicle diagnostic port and get all stored codes and freeze frame data. You will want to write this information down just in case the code turns out to be intermittent. After recording all relevant information, clear the codes and test drive the vehicle until the code is cleared or the PCM enters ready mode. If the PCM enters ready mode, the code is intermittent and harder to diagnose. The condition that led to the persistence of P06B8 may even get worse before a diagnosis can be made. If the code is reset, continue with this short list of pre-tests.
When trying to diagnose P06B8, information can be your best tool. Search your vehicle information source for technical service bulletins (TSBs) that match the stored code, vehicle (year, make, model, and engine) and symptoms displayed. If you find the correct TSB, it can provide diagnostic information that will help you to a great extent.
Use your vehicle information source to obtain connector views, connector pinouts, component locators, wiring diagrams, and diagnostic block diagrams relevant to the code and vehicle in question.
Use the DVOM to test the fuses and relays of the controller power supply. Check and replace blown fuses if necessary. Fuses should be checked with a loaded circuit.
If all fuses and relays are working properly, a visual inspection of the wiring and harnesses associated with the controller should be performed. You will also want to check the chassis and motor ground connections. Use your vehicle information source to obtain grounding locations for associated circuits. Use DVOM to check ground integrity.
Visually inspect the system controllers for damage caused by water, heat, or collision. Any controller damaged, especially by water, is considered defective.
If the power and ground circuits of the controller are intact, suspect a faulty controller or a controller programming error. Replacing the controller will require reprogramming. In some cases, you can purchase reprogrammed controllers from the aftermarket. Other vehicles / controllers will require onboard reprogramming, which can only be done through a dealership or other qualified source.
- Unlike most other codes, P06B8 is likely caused by a faulty controller or a controller programming error.
- Check the system ground for continuity by connecting the negative test lead of the DVOM to ground and the positive test lead to the battery voltage.
How to fix P06B8 Internal Control Module Non-Volatile RAM
Here are a few ways you can fix the OBD code P06B8.
- Replace or repair damaged or problematic PCM programming
- Replace or repair faulty control modules
- Repair or replace all relevant wires and connectors if damaged or problematic.
You have nothing to worry about because Parts Avatar - Car Parts Online is here to help you! We have high quality PCM, control modules, motor, short circuit, wiring harness, connectors, valve, ohmmeter and more for our valued customers.
Common Mistakes When Diagnosing Code P06B8
A common mistake you are likely to make when diagnosing this P06B8 error code is to ignore the following failures:
- Powertrain Control Module (PCM) Failure
- Wiring problem
Need more help with the P06B8 code?
If you still need help with DTC P06B8, post a question in the comments below this article.
NOTE. This information is provided for informational purposes only. It is not intended to be used as a repair recommendation and we are not responsible for any action you take on any vehicle. All information on this site is protected by copyright.
3 comment
Alberto Manotas
Good information, well detailed.
Eliandro
My car (Ecosport 1.6 freestyle 2014) shows error P06B8 intermittently,
When it happens, the car does not start and I lose the operation of the air conditioning when the car starts again, I noticed that when I put the key in the ignition to start and shake the same, it starts working again, causing this error and the shutdown of the engine. air, which will only return if I remove the battery (reset) from the vehicle. What can it be?
Julius Caesar.
Good morning, check the connectors and connections of the BSI wiring system in the passenger compartment and the outside of a 3 Citröen C2020 diesel and the P06B8 fault persists, it is the only fault code or DTC that is not erased, I followed the instructions to the letter. steps to follow and the only thing left to do is to have the BSI checked by an expert electronics technician since he has the necessary tools to diagnose and repair, but if you have one last piece of advice I would appreciate it.