How to Reset a Subaru Transmission Control Module?

You may need to reset the Transmission Control Module (TCM) of your Subaru if you encounter transmission issues.

In this comprehensive guide, we’ll cover all the options you have for resetting your Subaru’s TCM. Besides reviewing the signs of faulty TCMs, we’ll also discuss what to look for.

Reset a Subaru Transmission Control Module

Table of Contents

What are the benefits of resetting your Subaru’s TCM?

Resetting your Subaru’s TCM can be required for several reasons:

Shifting that is erratic or rough
Repairs or maintenance of transmissions
Error codes related to transmissions can be cleared
Increasing the efficiency of transmissions

Most transmission problems can only be resolved by resetting the Transmission Control Module (TCM).

Resetting the TCM in your Subaru

In order to reset your Subaru’s TCM, you can choose from four primary methods. Let’s take a closer look at each of them.

Method 1: Using the gas pedal

Start the engine without starting the ignition by inserting the key into the ignition.
Make sure the kick-down switch is engaged by pressing the gas pedal down. Keep your fingers pressed for 10-15 seconds.
The gas pedal should be released once the ignition has been turned off.
Your vehicle’s electrical systems should not be touched for five minutes.
Adapt the transmission to your driving patterns by driving your Subaru normally.

Method 2: Disconnecting the battery

Put the vehicle in park or neutral and turn off all electrical accessories.
You don’t have to start the engine. Just turn the ignition on. Give it 15-20 seconds.
Allow 10-15 seconds to pass after you turn off the ignition.
3-5 minutes should be sufficient for a hard reset after disconnecting the negative battery terminal.
The vehicle should be started after the battery is reconnected. The TCM needs to be recalibrated after a few minutes of idling.
Allow the TCM to adjust by testing the vehicle in different conditions.
If the transmission performance needs to be improved or further diagnostics are needed, monitor its performance.

Method 3: Release the accelerator pedal

The ignition key must be turned to the “On” position before starting the engine. The gas pedal must be pressed all the way down before starting the engine.
Put the ignition key in the “Off” position while keeping the gas pedal depressed.
Take your foot off the gas pedal.
Approximately 30 seconds should pass.
Restart the engine without turning the ignition key.
Hold the gas pedal for 30 seconds then fully depress it again.
Put the key in the “Off” position and let go of the gas pedal.

Method 4: Scanners for OBD

Your Subaru’s TCM can be reset with the help of an OBD (On-Board Diagnostic) scanner. Using one is as simple as this:

The cost of an OBD scanner is affordable no matter where you buy it from. Local auto parts stores or online retailers sell them.
Under the dashboard on the driver’s side, you will usually find your vehicle’s OBD port.
You must turn on the OBD scanner once you have plugged it into the port.
You can reset or reprogrammed your scanner by following the prompts on the screen.
If you want to reset your TCM, follow the scanner’s instructions carefully.

Note: If you are uncertain about how to use an OBD scanner, how its results should be interpreted, or what to do with them, consult a qualified mechanic. You want to prevent your vehicle from sustaining unintended damage.

TCM Faults: The Signs and Symptoms

TCM issues can be addressed before they become more serious if you know the signs of a failing TCM. The following symptoms are common:

Symptom	Description
Shifts that are rough or erratic	A smooth and predictable shift should be possible with your transmission. It may be your TCM that is causing erratic or rough shifting.
Check Engine Light	Regardless of whether a check engine light indicates a variety of problems, if it appears alongside transmission issues, your transmission control module should be investigated.
Limp Mode	When your TCM fails, your car goes into “limp mode,” reducing performance to protect it.
Shifts in neutral that are unexpected	An issue with the TCM would cause your vehicle to shift randomly into neutral or refuse to shift at all.

Getting Professional Help When You Need It

A professional mechanic’s assistance is often best if your Subaru’s TCM needs to be reset in order to solve transmission problems.

You should always seek the advice of a reliable mechanic if you are unsure about how to reset the transmission or if your transmission problems persist after you have attempted to reset it.

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Conclusion

If your Subaru is experiencing transmission issues, you may need to reset its Transmission Control Module to restore the vehicle’s performance to its optimum level.

You should be able to overcome this task confidently or seek professional assistance when necessary when you understand how to reset a TCM, as well as the symptoms of faulty TCMs.

You can prevent more serious and costly repairs down the road by maintaining your vehicle regularly and paying attention to its performance.

What are the benefits of resetting your Subaru’s TCM?