P062C Internal vehicle speed control module

P062C Internal vehicle speed control module

OBD-II DTC Datasheet

Internal Control Module Vehicle Speed

What does this mean?

This is a generic transmission diagnostic trouble code (DTC) and is commonly applied to OBD-II vehicles. This may include but is not limited to vehicles from, etc. Despite the general nature, the exact repair steps may vary depending on the year, make, model and transmission configuration.

When the P062C code persists, it means the powertrain control module (PCM) has detected an internal performance error with the vehicle speed sensor (VSS) signal. Other controllers may also detect an internal PCM performance error (in the VSS signal) and cause P062C to be stored.

The internal control module monitoring processors are responsible for the various controller self-testing functions and the overall accountability of the internal control module. The VSS 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 can communicate with the VSS signal.

The VSS is usually an electromagnetic sensor that interacts with some type of toothed reaction ring, wheel or gear that is mechanically attached to an axle, transmission / transfer case output shaft, or drive shaft. As the axis rotates, the reactor ring also rotates. When the reactor passes (in close proximity to) the sensor, notches in the ring of the reactor create interruptions in the electromagnetic sensor circuit. These interrupts are received by the PCM (and other controllers) as waveform patterns. The faster the waveform patterns are entered into the controller, the higher the vehicle's design speed. As the input waveforms slowly, the vehicle speed estimate (perceived by the controller) decreases. These input signals are compared (between modules) via a Controller Area Network (CAN).

Whenever the ignition is turned on and the PCM is energized, the VSS signal 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 a VSS I / O mismatch, a code P062C will be stored and a malfunction indicator lamp (MIL) may illuminate. In addition, if the PCM detects a mismatch between any of the onboard controllers, indicating an internal VSS error, a P062C 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.

Photo of the PKM with the cover removed:

What is the severity of this DTC?

Internal Control Module processor codes are to be classified as Severe. A stored P062C code may result in erratic automatic transmission shift patterns and erratic speedometer / odometer performance.

What are some of the symptoms of the code?

Symptoms of a P062C trouble code may include:

• Unstable operation of the speedometer / odometer
• Irregular gear shifting patterns
• Emergency engine lamp, traction control lamp or anti-lock brake system lamp illuminates
• Unexpected Activation of Anti-lock Braking System (If Equipped)
• Traction control codes and / or ABS codes can be stored
• In some cases, the ABS system can fail.

What are some of the common causes for the code?

Causes of this P062C DTC may include:

• Faulty controller or programming error
• Excessive accumulation of metal debris on the VSS
• Damaged or worn teeth on the reactor ring
• Bad VSS
• Faulty controller power relay or blown fuse
• Open or short circuit in the circuit or connectors in the CAN harness
• Insufficient grounding of the control module
• Open or short circuit in a chain between VSS and PCM

What are some steps to troubleshoot the P062C?

Even for the most experienced and well-equipped professional technician, diagnosing the P062C code can be quite 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 P062C. In addition, if VSS codes are present, they must first be diagnosed and repaired.

There are some preliminary tests that can be performed before an individual controller is declared faulty. You will need a diagnostic scanner, a digital volt-ohmmeter (DVOM) and a source of reliable information about the vehicle. The oscilloscope will also prove useful for testing VSS and VSS circuits.

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 standby mode. If the PCM enters ready mode, the code is intermittent and harder to diagnose. The condition that caused the P062C to persist 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 a P062C, 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.

You can use a scanner (data stream) or oscilloscope to check the VSS output with the transmission engaged. If you are using a scanner, narrowing the data stream (to display only the relevant fields) will improve the accuracy of the display of the required data. Watch for inconsistent or erroneous VSS readings.

The oscilloscope provides more accurate data sampling. Use the positive test lead to test the VSS signal circuit (the negative test lead is grounded to the battery). Watch for interruptions or surges in the VSS signal circuit waveform.

If required, the DVOM can be used to test the resistance of the VSS sensor (and VSS circuits). Replace sensors that do not meet manufacturer's specifications.

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, P062C 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.

Related DTC discussions

• 2008 ford crown vic P062c codeI worked on this car for a couple of days, I got the code p062c, replaced the engine wiring harness with a checked one, replaced the PCM, replaced the transmission, still dives well until you get to overload, then the wrench light without OD comes on, If I turn off the OD , the car will go fine, but not right ?? Anybody have… 

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