Fault code P0614 is called “ECM/TCM Incompatible” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.
Technical description and explained code P0614
OBD-II trouble code P0614 is defined as “compatibility problem between engine control module (ECM) and transmission control module (TCM). It is set when a compatibility error or component failure is detected in the ECM/TCM.
Regarding code P0614 and its description, the word “incompatibility” refers to the disruption of effective communication between the ECM and the TCM. This communication takes place in the form of input data received from numerous sensors and other control units.
The data is distributed to all relevant control units via the CAN bus system. Typically, the ECM acts as an “information hub” for all input data received.
In order for the ECM to effectively control all engine functions, it needs accurate and reliable data from several control units.
If faults or malfunctions occur in the ECM and TCM or in the wiring of the CAN system bus. Which prevents effective communication between the various control units affected by the shift request.
The PCM will interpret the communication failure as an incompatibility between itself and the TCM and as a result will set code P0614. Depending on the operating conditions, a warning light may also illuminate.
In some cases the code will be present as “pending” until the required number of failure cycles occur.
Symptoms of vehicle malfunctions
The main signal that an error P0614 has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.
It can also be warning signs such as:
- The “Check engine” control lamp on the control panel will light up (the code will be memorized as a fault).
- Other related fault codes may also be present.
- There may be no symptoms other than the stored fault code.
- Sharp, erratic, or unpredictable gear shifting.
- Transmission may not shift at all.
- The speedometer does not work or does not work correctly.
- Engine stalls or fails to start.
- Floating revolutions, as well as attempts to stall at idle.
- Increased fuel consumption.
Fault P0614 is quite serious, as it can cause problems with gear shifting and vehicle handling. To avoid the problem worsening, it is recommended to eliminate the cause as soon as possible.
Factors that can cause this error code
The error code P0614 can mean that one or more of the following problems have occurred:
- Faulty ECM/TCM module.
- ECM/TCM programming error.
- Damaged, corroded wiring or connectors.
- Open or short circuit in CAN bus line.
- Control box fuse blown.
- Low battery voltage.
How to fix or reset OBD-2 code P0614
Some suggested steps for troubleshooting and fix the error code P0614:
- Inspect the wiring for damage, abrasions, breaks, and shorts. If the wiring is damaged, repair or replace it.
- Disconnect and test each CAN bus pin with a special diagnostic scanner.
- Inspect and check the fuse and fusible link.
- Check the condition of the battery pack.
- If the problem persists, the ECM/TCM module may need to be replaced and reprogrammed.
Diagnose and repair of problems
Diagnosing the P0614 code can be a daunting task even for the most experienced and well-equipped technician. However, there are a few preliminary tests that can be performed before calling for service to replace the ECM/TCM.
You should start with a visual inspection of all visible wires and harnesses associated with the vehicle’s controllers. Using a multimeter, check the ground to the engine and bodywork to make sure they are OK.
Battery connection
To rule out all possibilities of fault P0614, you should visually inspect the wiring, check the voltage on the battery. You should also check the battery terminals and cables for loose connections.
Ensure that the system voltage is as specified in the manual. The charging system is fully operational and the battery is in good condition, begin the diagnostic procedure.
Further verification
Locate the ECM/TCM control unit and inspect it for damage caused by water, heat, or collision. If the ECM/TCM is damaged, especially by water, it is likely out of service and needs to be replaced.
Next, check the ECM/TCM power supply fuses and relays. Inspect and replace the blown fuses as well as the relay connector.
If the ECM/TCM power supply code is also present along with fault P0614, correct it first before troubleshooting this fault.
After the tests are done, recheck for the error, if it remains, the ECM/TCM module is most likely faulty. Replacing the ECM/TCM or any other controller usually requires reprogramming for the specific vehicle.
On which vehicles does this problem occur most frequently
Fault code P0614 can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:
- Audi
- Ford (Mondeo)
- Mazda
- Nissan
- Volkswagen
- Volvo
Fault code P0614 can sometimes be found with other errors. The most common are the following: P0113, P0606, P0613, P0700.
