Technical Description of OBD-II Trouble Code
The performance of the internal control module drive motor/generator – engine speed sensor is being evaluated.
What does that signify?
This generic powertrain diagnostic trouble code (DTC) is applicable to various OBD-II vehicles, including Tesla, Toyota, Nissan, Ford, Chevrolet, BMW, etc.
When the code P0C2F is stored, it indicates that the powertrain control module (PCM) has detected an internal processor performance error in the drive motor/generator – engine speed sensor circuit. Other controllers may also detect an internal PCM performance error in the drive motor/generator – engine speed sensor and store a P0C2F code.
The code P0C2F is exclusively used for total electric and hybrid vehicles.
Internal control module monitoring processors are responsible for performing various self-tests and ensuring overall accountability of the internal control module. The PCM and other related controllers constantly monitor the input and output signals of the ignition coil control system through self-tests. The drive motor/generator – engine speed sensor circuit also interacts with the transmission control module (TCM), traction control module (TCSM), and other controllers.
The drive motor/generator – engine speed sensor is typically an electromagnetic sensor that interacts with a toothed reluctor ring, wheel, or gear attached to the drive motor/generator armature shaft. As the drive motor/generator spins, the reluctor ring also spins. When the reluctor passes by the sensor in close proximity, the notches in the reluctor ring create interruptions in the electromagnetic sensor circuit. The PCM and other controllers receive these interruptions as waveform patterns. The controller estimates the drive motor/generator – engine speed based on the frequency of these waveform patterns. A decrease in the frequency of waveform patterns indicates a decrease in the estimated drive motor/generator – engine speed. These input signals are compared between modules through the controller area network (CAN).
Self-tests of the drive motor/generator – engine speed sensor system are initiated whenever the ignition is on and the PCM is powered. In addition to running internal controller self-tests, the controller area network (CAN) also compares signals from each individual module to ensure proper functioning of each controller. These tests are performed simultaneously.
If the PCM detects an internal discrepancy in the drive motor/generator – engine speed sensor system processor, it stores a code P0C2F and may illuminate the malfunction indicator lamp (MIL).
If the PCM detects a problem between any of the on-board controllers, indicating an internal drive motor/generator – engine speed sensor system error, it stores a code P0C2F and may illuminate the malfunction indicator lamp (MIL). Depending on the perceived severity of the malfunction, multiple failure cycles may be required for MIL illumination.
Example photo of a PCM:
What is the severity of this DTC?
Codes related to internal control module processors should be considered severe. A stored code P0C2F can result in various drivability concerns.
What are some of the symptoms of the code?
Symptoms of a P0C2F trouble code may include:
What are some of the common causes of the code?
Possible causes for this code may include:
What are some P0C2F troubleshooting steps?
Diagnosing a code P0C2F can be challenging even for experienced technicians. Reprogramming may also be necessary for controller replacement, which requires the appropriate equipment.
If there are ECM/PCM power supply codes present, they should be addressed before attempting to diagnose a P0C2F.
Prior to declaring any controller defective, several preliminary tests can be performed. These tests require a diagnostic scanner, a digital volt/ohmmeter (DVOM), and reliable vehicle information.
Connect the scanner to the vehicle diagnostic port and retrieve all stored codes and freeze frame data. Record this information in case the code is intermittent. After recording the information, clear the codes and 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 more difficult to diagnose. In some cases, the condition that caused the P0C2F to be stored may need to worsen before a diagnosis can be made. If the code is reset, continue with the following preliminary tests.
When diagnosing a P0C2F, information is crucial. Search for technical service bulletins (TSB) that match the stored code, vehicle (year, make, model, and engine), and exhibited symptoms. The right TSB may provide diagnostic information that can greatly assist in the diagnosis.
Use the vehicle information source to obtain connector face views, connector pin-out charts, component locators, wiring diagrams, and diagnostic flow charts related to the code and vehicle in question.
Use the DVOM to test controller power supply fuses and relays. Replace blown fuses as necessary. Fuses should be tested with the circuit loaded.
If all fuses and relays appear to be functioning properly, visually inspect the wiring and harnesses related to the controller. Also check the chassis and engine ground junctions. Use the vehicle information source to locate the ground locations for the related circuits. Use the DVOM to test the integrity of the grounds.
Visually inspect the system controllers for signs of water, heat, or collision damage. Any damaged controller, especially due to water, should be considered defective.
If the power and ground circuits of the controller are intact, suspect a defective controller or a controller programming error. Controller replacement will require reprogramming. Aftermarket sources may offer reprogrammed controllers for some vehicles. Other vehicles/controllers may require on-board reprogramming that can only be done through a dealership or qualified source.
