P0614 ECM/TCM Incompatible
OBD-II Trouble Code Technical Description
ECM/TCM Incompatible
What does that mean?
This generic powertrain diagnostic trouble code (DTC) typically applies to many OBD-II vehicles. That may include but is not limited to vehicles from Ford, VW, Nissan, Volvo Mazda, Audi, etc.
A stored code P0614 means that a compatibility issue has occurred between the engine control module (ECM) and the transmission control module (TCM).
In some cases, the ECM and TCM may be separate from one another. More often, they are integrated into a single module known as the powertrain control module (PCM). This increases controller effectiveness in addition to saving automakers space, time, and money.
Each time the ignition is turned on and the PCM is energized, multiple controller self-tests are performed. In addition to running internal controller self-tests, the controller area network (CAN) is used to compare signals from each individual module to ensure that the various controllers are interacting properly.
In monitoring ECM/TCM compatibility, if a discrepancy is detected, a code P0614 will be stored and a malfunction indicator lamp (MIL) may be illuminated. Depending upon the perceived severity of the malfunction, multiple failure cycles may be necessary for MIL illumination.
Example of a transmission control module:
What is the severity of this DTC?
Internal control module codes must always be taken seriously. A stored code P0614 could result in a variety of drivability and automatic transmission concerns.
What are some of the symptoms of the code?
Symptoms of a P0614 trouble code may include:
Engine drivability issues Engine stall or no-start Erratic transmission shift patterns Harsh transmission shifting Inoperable or inaccurate speedometer/odometer Other stored ECM/TCM codesWhat are some of the common causes of the code?
Causes for this code may include:
Faulty ECM/TCM ECM/TCM programming error Open or shorted circuit or connectors in the CAN harness Failed ECM/TCM power source Insufficient control module groundWhat are some P0614 troubleshooting steps?
Unfortunately, even the most experienced and well-equipped professional technician may find diagnosing a code P0614 to be quite a challenge. There is also the issue of reprogramming. Without the necessary reprogramming equipment, it will be impossible to replace a defective controller and complete a successful repair.
If ECM/TCM power supply codes are present, they will need to be repaired before attempting to diagnose a P0614.
There are several preliminary tests that can be performed prior to declaring any controller defective. A diagnostic scanner, a digital volt/ohmmeter (DVOM), and a source of reliable vehicle information will be required.
Connect the scanner to the vehicle diagnostic port and retrieve all stored codes and freeze frame data. You will want to write this information down, just in case the code proves to be an intermittent one. After recording all pertinent 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. The condition, which caused the P0614 to be stored, may even need to worsen before a diagnosis can be made. If the code is reset, continue with this short list of preliminary tests.
When attempting to diagnose a P0614, information may be your greatest tool. Search your vehicle information source for technical service bulletins (TSB) that parallel the code stored, vehicle (year, make, model, and engine), and symptoms exhibited. If you find the right TSB, it may yield diagnostic information that will aid you in a major way.
Use your source of vehicle information to obtain connector face vie
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