How do you reset a transmission control module?

The transmission control module is the one that controls all of your vehicle’s speed, acceleration, and shifting functions. It interacts with other modules like the engine control module and instrument cluster to do what it is supposed to do. Our focus here is on how do you reset a transmission control module?

To reset the transmission control module, you should turn-key ignition, press the gas pedal, wait a while, turn the key off, release the gas pedal, wait a while, and turn-key ignition for identification.

The module has been known to fail in some cases but will not cause your vehicle to stop running unless there is a short in the wiring harness. However, when it fails, you can always reset it to get your car back to its normal condition.

What is the transmission control model?

How do you reset a transmission control module

The transmission control module is a module of the automatic transmission system on a car or truck. The TCM controls the automatic transmission’s hydraulic functions through solenoid valves and clutches and monitors the engine throttle position, vehicle speed, and transmission gear selection.

The TCM allows paddle shifters built into some modern automatic transmissions. It lets you change gears manually without touching the stick shift; instead, you can use (or feel) a button in your car’s steering wheel or console designed for this purpose.

Also, it is a specialized computer designed to regulate and monitor the broad array of components that make up your vehicle’s automatic transmission.

Composed of hardware and software, it continuously performs several highly complex operations like data processing, monitoring, regulation, and control.

While you can’t say you ever really notice it, there would be no way to operate your automatic transmission without this specialized unit.

How do you reset a transmission control module?

How do you reset a transmission control module

To reset the transmission control module, you need to follow the steps to get the right outcome.

Turning key position 

The first step is turning the key position of the car. It doesn’t require you to start the car. All you need to do is turn the key to the ACC, where you have all other active car functions. Also, you need the car to be in a parked position to do any reset successfully.

Press the gas pedal and wait

The next step you should do is press the accelerator pedal with your leg and ensure you push it down to the car’s floor. Once you do, you should wait for about a few minutes, and one minute is never too long.

Turn the key off

While you have the pedal pushed to the floor, you need to switch off the car. Leave the key and do not remove it from its housing. Then you can move on to the next task.

Release the gas pedal

Now that you have the key to its previous position known as off, then you should gently let go of the pedal. You should wait a while and then turn in the car, and you can go on to drive. This way, you have been able to reset the TCM.

Transmission control module fuse?

How do you reset a transmission control module

A transmission control module fuse supplies power to the transmission control module (TCM). The TCM monitors actual gear speeds and controls shifting through the transmission.

Therefore, a malfunction in this system can lead to gear problems, such as repeated grinding, jumping out of gear, or you may even lose all forward gears.

In any case of malfunctioning, you can always replace the fuse. Your transmission control module (TCM) fuse may need to be replaced from time to time.

Also, a blown a fuse is not dangerous for your transmission because it acts as a safeguard for the transmission. If you think that your TCM fuse is blown, your next step should be to contact a certified mechanic or the dealership.

How do you reset a transmission control module

How to flash a transmission control module?

To flash the transmission control module for your car, you need to use a scan tool capable of communicating with computer chips. A laptop computer and the scan tools should accomplish this task with ease.

The transmission control module is located under the dashboard of most cars. You can usually find it by following your odometer.

The transmission control module is responsible for several components in your car’s transmission, including the throttle and the wastegate actuator.

Flashing a transmission control module can be time-consuming but well worth the effort if you want to experience greater efficiency and better performance from your car without having to replace it apart.

To flash your TCM:

  • Park the car and turn it off.
  • Remove the fuel pump fuse.
  • Turn the wheel to one side and then back to the center
  • It puts the TCM in learn mode to receive its new programming

Press the accelerator pedal three times within five seconds and release (this clears any stored fault codes). Press and hold down the “T” button on the upper left-hand corner of the TCM while plugging in your laptop. The screen should read “Transmission Control Module – Write EEPROM.” At this point, release the “T” button and use your laptop’s serial cable to connect to T40 connector C1 of the TCM (refer to pictures below for location).

You must properly connect your serial cable before releasing the “T” button from its depressed state. At this point, you can send hex values from whatever software you are using to program your PCM.

Read also: Starting a car that has been sitting for 6 months

Will disconnecting battery reset TCM?

To reset the TCM, you have to disconnect the battery and put it back on, but that only clears the fault code; there could be something wrong with the relays somewhere or a fuse that might not be reset.

Disconnecting the battery doesn’t reset the TCM. You need to go through some processes to reset the TCM for the right result.

How to test the transmission control module?

Testing the transmission control module (TCM) is important for diagnosing problems with your car’s transmission. However, since there are many different makes and models on the road today, it’s difficult to find a particular diagnostic test procedure.

To test the transmission control module, you will need a voltmeter with an ohm scale feature. You need to know the color code connections and locations to connect the voltmeter alligator clips.

However, it should never be done at home if you don’t know what to do.

Will a bad TCM throw a code?

Yes, a bad TCM will throw a code either P2135 or P2135. This is a progressive diagnostic code. If you have codes of this variety, proceed to test the various components and replace found faulty ones. To have your computer scanned for any trouble codes, you must take it to a certified or experienced mechanical shop.

A bad transmission control module (TCM) will not cause the check engine light to come on. There are also no driveability concerns related to a bad or malfunctioning TCM. This applies if the vehicle is utilizing the carbureted style of transmission.

The only time a fault code would be set related to the TCM is if there is an internal problem such as short or missing pulses from one of the circuits inside it.

Typically, you will be able to see this on a diagnostic scan tool such as TIS2WEB or AutoTap, depending on which software your mechanic uses, and they can tell you what codes are being set by it.

What causes a transmission control module to fail?

There are a variety of reasons why a transmission control module can fail. Faulty internal components or wire harnesses can cause the module to malfunction. Corrosion, accumulated dirt, and water in surrounding components can also affect functionality.

Also, improper fluid level or improper fluid type, and contaminated fluid can cause protection circuits to shut down after a few minutes of operation. Finally, if there are any accidents or excessive shifting caused by external damage, the TCM will not operate accordingly.

Read also: Why does my steering wheel lock when parked?

How can I tell if my TCM is bad?

A bad TCM can lead to many problems with your car/truck, including an inability to start the car, random stalling and shaking, and no or intermittent crank. Inspecting and repairing or replacing the TCM is an option for many owners; however, if you cannot diagnose or repair the TCM yourself, you should have it replaced with a new part.

Is there a fuse that controls transmission?

Yes, there is a fuse that controls the transmission, and it is called a transmission control module. The fuse box is located in the engine compartment. It can be opened by the top cover and on the left side.

To access the fuse box, you need to remove the air cleaner cover, unhook a wire, and push back one or two wires depending on the vehicle year since there is a different fuse panel under the hood that controls this function.

Can a bad TCM cause a car not to start?

A bad transmission control module (TCM) will not cause your car to not start. The transmission control module or TCM controls the shifting in an automatic transmission and activates vacuum-operated shifting devices, like in older manual transmissions.

What is transmission reflash?

Transmission reflash is an inexpensive and effective way to improve transmission shift parameters in many transmissions. Reflash can be performed using approved OBD-II compliant tools (or appropriate subscription) via the Diagnostic Link Connector (DLC) connector under the dash of most Ford, GM, or Chrysler vehicles.

After reflash, the driver feels a smoother shifting experience and sees lower transmission temperatures and improved fuel economy due to more efficient shifting. Transmission reflash is a safe and inexpensive alternative to rebuilding your transmission.

Also, Transmission reflash is a similar process to engine performance tune-up. This process improves transmission efficiency while decreasing energy loss and saving fuel economy. Transmission reflash ensures that there is no delay in gears shifts, and it will make your car smoother to drive.

It also helps to enhance the overall performance of the vehicle at a cheap cost. Transmission reflash is safe for any car, and this service can be performed by any authorized mechanic or auto expert without taking your car apart.

Where is TCM located?

Your vehicle’s transmission control module (TCM) houses computers that manage your automatic transmission’s speed, acceleration, and other functions. Under the hood, you’ll find a small engine compartment fuse box with wires that lead from your TCM to relays and fuses.

One of these is the transmission control module (TCM) fuse, which protects and controls electrical power for the TCM.

What does resetting a transmission do?

Resetting a transmission is a simple, quick process that can help fix issues with your transmission. In most cases, resetting a transmission is as easy as pushing a button and waiting for a few seconds.

Done right resetting a transmission can fix vibrations, improve smoothness and mileage, reduce the frequency of service and repair, and extend the life. Transmissions that have been sitting for months or even years without being used are likely to have excess sludge build-up inside and debris such as leaves, grass, dirt, and sand in the gears.

Also, resetting a transmission uses special tools to pump out old fluid, blow out all the junk that has accumulated and re-fill it with fresh fluid–that’s the “fix” that can be done when all other attempts to get your car, truck, or SUV’s transmission working well again have failed.


There are ways you can reset your TCM. We focused on this page to answer the question. How do you reset a transmission control module? You should find it easy to do with the information here as long you have mechanical knowledge on how to do it.