A part of the system that controls shift points on an automatic transmission is known as the transmission control module.
If your Chevy isn’t shifting as well as it should, it might be time to get a new one. If you attempt to reset it, you should check to see if that solved the problem.
If you want to reset the transmission control module in a Chevy, you must disconnect it for 10 to 30 minutes.
On the driver’s side of the engine bay is where it is located. The built-in lever is all that is needed to connect and reconnect the TCM.
Transmission Control Module: What is It?
The transmission control module works with other components to determine when the automatic transmission should switch gears.
The current speed and load placed on the vehicle are taken into account by the TCM so it can shift gears at the best possible moment.
When you step on the gas hard the engine will shift down, which will provide more power and less fuel consumption. Otherwise, the gear shifts are oriented toward economy mode.
The gears should be adjusted to the situations of uphill and downhill driving, according to the transmission control module.
The driver needs to manually shift the gear lever into “3” or “L” gear to prevent unnecessary shifts on older transmission systems.
Symptoms of a Bad TCM
The transmission control module failure is accompanied by at least one symptom.
It will be easier to tell when the TCM needs to be changed if you know how these symptoms present themselves.
Dashboard Warning Light
The check engine light or the check transmission light is a sign of an issue with the transmission control module.
It will appear before the real symptoms so you can address the problem before it happens.
The error code can be read directly from the center dash on modern vehicles, but if you want to know the exact problem, you need to use an OBD2 scanning device.
If the scanner only gives you a code, you should keep an eye out for P0611, P0700, and P0706 as these are some of the codes related to the problem.
There is a faulty transmission control module and hard shifts are a symptom. When it is time to shift gears on your Chevy, it will cause a power delay and a jerk as the gear falls in.
The symptom may be caused by the transmission itself, but at the very least you can reset the TCM before conducting further investigation.
Failure to Shift
Failure to shift gears is the most serious symptom of the transmission control module.
Even though the transmission goes up a couple of gears, it fails to shift further when the RPM is high.
The symptom can happen on downshifts which would cause the engine to stall.
If you don’t diagnose and fix the problem when your transmission reaches this stage, you will put yourself and the vehicle at risk.
Locating the TCM
The transmission control module will be located in an easy-to-reach spot on most Chevy models.
You can take a look at the area on the driver’s side of the engine bay if you lift the hood.
The transmission control module has a large metal housing bolted onto the body with a large cable attached to it.
4l60e TCM Location
The 4l60e TCM is located behind the cover of the transmission case and is a specific module for Chevy.
It can be found underneath the passenger’s side of the engine bay on some cars or next to the engine’s control module on others.
The 4l60e had one version update over 20 years. The 4l60 was used by Chevy from 1990 to 1992 and the 700R4 from 1982 to 1989.
Resetting the TCM
There are three ways to reset the transmission control module.
- Disconnect the battery leads.
- Disconnect the TCM.
- Follow the reset procedure.
The second method is the most reliable, but it may be more complicated if the TCM is located in an inconvenient spot.
We will go through each method in detail, and you can try one or all of them to get the desired results.
Disconnect the Battery Leads
If you disconnected the positive and negative terminal of the battery you could leave the car for 30 minutes.
The electrical components like ECU and TCM will drain completely, and those without permanent storage will need to be reset.
The transmission control module may have some memory built-in, as some learn from the driver’s habits and adjust transmission accordingly. This method won’t work for the models.
Disconnect the TCM
The most effective way of resetting the transmission control module is to remove the power and data cable.
The upper driver-side corner of the engine bay is where the TCM is located on most Chevy vehicles, as explained in the previous section.
Don’t forcefully yank the transmission control module, it’s secured in place through a mechanism, and it’s connected to a large cable.
The safety latch will either be a lever or a series of plastic or metal clip-on pins.
As a precautionary measure, it is a good idea to disconnect the battery before pulling the plug. Take the cable out and leave it there for a few minutes.
If the transmission control module is working as expected, you need to re-connect the battery and the TCM.
Follow the Reset Procedure
Most of the time, the reset procedures require you to press the control pedals and then turn the key, which is quite strange.
The majority of the cases work because these procedures were built in by the manufacturer to make certain resets easier.
Steps to follow:
- Set the ignition to on.
- You can press the gas pedal down and hold it for a few seconds.
- Release the pedal after turning off the ignition.
- Wait 1-2 minutes without touching the vehicle’s controls.
- Start the vehicle, drive normally, and don’t push the engine for 100 shifts.
How to Change TCM?
It is as easy to change the transmission control module as it is to reset it, and you only need to remove the screws.
How you handle the new TCM is the only thing that needs to be watched over. Think of it as a delicate computer part instead of a robust car component.
Even though it has a protective case, it is still prone to impact and shock damage, so be careful.
Is It Possible to Reset My TCM?
If your vehicle is having transmission issues, it is a good idea to change the transmission control module.
Replacing the TCM can cost hundreds of dollars, and resetting it is a free solution to the problem.
Is It Possible That Disconnecting the Battery Will Reset TCM?
The battery can be disconnected enough to reset the TCM on some vehicles.
When the system is drained of power, the internal storage of the transmission control module will retain the shifting habits and the issue will persist.
If you want to get the TCM to reset, combine the three procedures and follow the manual reset by turning the key and pressing the gas pedal.
How Much Does It Cost to Reprogram a TCM?
The rest is free, and you may only need to pay a small fee or tip the mechanic for executing the procedure correctly.
Transmission control modules are very expensive and can easily set you back $500 or more if you are looking at a TCM change.
Does a 4l60e Have a TCM?
Typically, the 4l60e is coupled to an E38 or E40 ECM and a Chevy or other GM transmission.
If you need to disconnect the transmission control module, it is easy to locate it on most Chevy vehicles.
The reset procedure is very easy to perform, just a matter of turning the ignition, applying gas, and waiting.
The 4L60E should work on almost all Chevy cars.
Truck driver by profession, automotive lover by heart. Ricky is the main publisher and editor at Truckile.com sharing his life-long knowledge and experience in the auto industry and truck driving!