Transmission Control Module Replacement Cost

Know what price you should pay to get your vehicle fixed.

The average cost for a transmission control module replacement is between $624 and $720. Labor costs are estimated between $35 and $111 while parts are priced between $589 and $609. Estimate does not include taxes and fees.
Get a repair estimate for your car

What is a transmission control module?

The transmissions in most modern cars are controlled electronically, by an independent transmission control module (TCM), which is a dedicated portion of the powertrain control module (PCM). The controls vary by manufacturer, year and model of vehicle. The TCM communicates with several other vehicle systems to determine the best settings for the transmission at any given time, and change those settings efficiently based on pre-programmed information. The TCM also analyzes the operation of the transmission to ensure it is working as intended, and to alert the driver when there’s an issue. The TCM plays a big role in automatic transmissions, but manual transmissions also have control module to communicate with for things like vehicle speed, temperature, or even electronic shifting in dual-clutch transmissions.

How does the transmission control module work?

The systems the TCM may communicate with can include the engine control module, body control module, anti-lock brake system, instrument cluster, traction control system and even the radio. For instance, the TCM will tell the speedometer how fast the vehicle is moving, it may tell the radio that the speed is great enough for wind noise to drown out the speakers, or it could tell the engine control module to prevent the engine from starting when the vehicle is not in park.

Find a Certified Mechanic

Find a high quality auto repair shop or dealer near you

What are the symptoms of a bad transmission control module?

When the TCM fails, it may make erroneous calculations, fail to connect, fail to operate, or fail to interpret data correctly. This will lead to frequent malfunctions in transmission operations and several other systems. The check engine light will come on, and a number of on-board diagnostic (OBD) trouble codes may be triggered. However, in many situations, a scanning tool can fail to connect to the malfunctioning TCM. The car’s symptoms depend on the impacted systems, and the worst-case scenario is that the vehicle becomes undrivable.

Can I drive with a bad transmission control module?

If the TCM fails, it’s likely to leave the car disabled or only functioning in one or two speeds. This “limp mode” means the vehicle will be all but useless until it’s repaired. If the TCM fails, it should be replaced and updated as soon as possible.

How often do transmission control modules need replacement?

The TCM is known to fail in certain cars, but most vehicles won’t experience this problem in their lifetimes. For those that do run into TCM failure, the most common mileage range is 75,000 to 125,000 miles.

How are transmission control module issues diagnosed?

When the TCM is suspected of failure, the technician will test each of its pins by comparing the current readings to what they’re supposed to be. With so many possible failure symptoms, reference materials will guide the technician through the process of locating the pins and wires that correspond to the issue at hand.

How is the transmission control module replaced?

Replacing the TCM is normally easy since it has to first be accessed for diagnostics. The hardest part can be finding the TCM. In most vehicles, it’s in the engine bay, but some manufacturers place it inside the car. In some vehicles, the TCM is even located in the trunk. Once it’s found and confirmed as the problem, the module can be unplugged and removed, and the replacement can be connected to the vehicle.

RepairPal recommendations for transmission control module issues

When dealing with electronic systems, especially if the issue pertains to a control module, we recommend thorough diagnostics before replacing parts. It would be very easy to spend hundreds of dollars on new components before realizing the issue is caused by something else.

What to look out for when dealing with transmission control module issues

If the battery is installed or jump-started incorrectly, the TCM can be destroyed, along with other sensors and wiring. In many such cases, the PCM connector, harness or pins inside the connector socket fail and cannot make a proper connection to the TCM or transmission. Except for a broken or missing pin, these items can be replaced, and the vehicle retested.

Can I replace the transmission control module myself?

Replacing the TCM on most vehicles is fairly easy, but finding it can require a bit of online research, or even just a hunt. In many cases, the TCM looks much like some of the other computers mounted in the vehicle, and removing a few panels to find the wrong module will quickly become frustrating. The new part will also need to be calibrated, a process usually best left to a professional.

19,509 people trusted RepairPal with their estimates this week!