What Does It Mean?
This generic powertrain diagnostic trouble code (DTC) typically applies to many OBD-II vehicles. This may include, but is not limited to, vehicles from Dodge, Ram (Cummins), Ford, Chrysler, etc.
When a P061C code is stored, it means the Powertrain Control Module (PCM) has detected an internal performance error within the engine speed (RPM) monitoring system. Other controllers may also detect an internal PCM performance error (related to the engine speed monitoring system) and contribute to storing a P061C.
The internal control module processor monitors are responsible for various controller self-test tasks and the overall responsibility of the internal control module. The input and output signals of the engine speed calculation system are self-tested and are continuously monitored by the PCM and other associated controllers. The Transmission Control Module (TCM), the Traction Control System Module (TCSM), and other controllers interact with the engine speed monitoring system.
The engine speed is monitored (by the PCM and other controllers) using input signals from the Crankshaft Position Sensor (CKP) and the Camshaft Position Sensor(s) (CMP). The desired engine speed is programmed into the PCM and other controllers. The actual engine speed is calculated using input data from the CKP and CMP sensors, as well as the Throttle Position Sensor (TPS) and other engine and transmission sensors. The desired speed is then compared to the actual speed.
Whenever the ignition is turned on and the PCM is powered up, internal engine speed monitoring self-tests are initiated. In addition to running internal controller self-tests, the Controller Area Network (CAN) also compares the signals from each individual module to ensure all controllers are functioning correctly. These tests are performed simultaneously.
If the PCM detects an internal error between the desired engine speed and the actual engine speed (which exceeds the maximum allowable threshold), a P061C code will be stored, and a Malfunction Indicator Lamp (MIL) may be illuminated. Several ignition cycles (with a fault) may be required for the MIL to illuminate.
Photo of a PCM with the cover removed:
Powertrain Control Module PCM
How Severe Is This DTC?
Internal control module processor codes should be classified as severe. A stored P061C code could lead to serious drivability and fuel economy issues, suddenly and without warning.
What Are Some of the Symptoms of the Code?
Symptoms of a P061C trouble code may include:
Hesitation or stumbling during acceleration
Engine misfires
Reduced power output
Engine misfire codes may also be present
What Are Some of the Common Causes of the Code?
Causes
of this code may include:
Faulty CKP / CMP sensor
CKP / CMP sensor connector contaminated with oil
PCM programming error or faulty PCM
Open or shorted circuit or connectors in the CAN bus
Insufficient control module ground
Open or shorted circuits between the CKP / CMP sensor(s) and the PCM
What Are the P061C Troubleshooting Steps?
Even for the most experienced and well-equipped professional technician, diagnosing a P061C code can be very challenging. There is also the issue of reprogramming. Without the necessary reprogramming equipment, it will be impossible to replace a faulty controller and perform a successful repair.
If ECM/PCM power codes are present, they will obviously need to be corrected before attempting to diagnose a P061C. Additionally, if there are CKP/CMP sensor or Throttle Position Sensor (TPS) codes, these should be diagnosed and repaired first.
Follow the manufacturer’s recommendations for testing the CKP, CMP, and TPS sensors. An oscilloscope can be particularly useful when testing electromagnetic sensors. Replace faulty components as necessary.
Several preliminary tests can be performed before declaring an individual controller faulty. A diagnostic scanner, a digital volt/ohmmeter (DVOM), and a reliable vehicle information source will be needed. An oscilloscope may also prove useful.
Connect the scanner to the vehicle’s diagnostic port and retrieve all stored codes and freeze frame data. You will want to note this information, just in case the code proves to be intermittent. After recording all relevant information, clear the codes and test drive the vehicle until the code resets or the PCM enters readiness mode. If the PCM enters readiness mode, the code is intermittent and will be more difficult to diagnose. The condition that caused the P061C to be stored may even need to worsen before a diagnosis can be made. If the code resets, proceed with this short list of preliminary tests.
When trying to diagnose a P061C, information can be your best tool. Search your vehicle information source for Technical Service Bulletins (TSBs) that correlate the stored code, the vehicle (year, make, model, and engine), and the symptoms presented. If you find the right TSB, it can provide diagnostic information that will help you significantly.
Use your vehicle information source to obtain connector face views, connector pinout diagrams, component locators, wiring schematics, and diagnostic flowcharts related to the specific code and vehicle in question.
Use the DVOM to test the controller’s power fuses and relays. Test and replace blown fuses as needed. Fuses should be tested under load.
If all fuses and relays appear to be functioning as expected, a visual inspection of the wiring and harnesses related to the controller is necessary. You will also want to check the chassis and engine ground junctions. Use your vehicle information source to obtain ground locations for the related circuits. Use the DVOM to test ground integrity.
Visually inspect the system controllers for signs of water, heat, or collision damage. Any damaged controller, especially by water, should be considered faulty.
If the controller’s power and ground circuits are intact, suspect a faulty controller or a controller programming error. Replacing the controller will require reprogramming. In some cases, you can purchase pre-programmed controllers through aftermarket sources. Other vehicles/controllers will require onboard reprogramming that can only be performed by a dealership or another qualified source.
Unlike most other codes, P061C is likely caused by a faulty controller or a controller programming error
Test the system ground integrity by connecting the DVOM’s negative test lead to ground and the positive test lead to battery voltage