Luka Kusic
Updated on September 16, 2022
The transmission control module, otherwise known as the transmission shift solenoid is a part of the system that controls shift points on an automatic transmission.
If your Chevy is suffering from erratic shifting or failure to change gears, it might be time to change the TCM. Before you do that, you should first try resetting it and checking if that solved the problem.
To reset the transmission control module in a Chevy, you must disconnect it for 10 to 30 minutes. It’s located on the driver’s side of the engine bay, right below the windshield. Disconnecting and reconnecting the TCM is simple and requires no tools – just operate the built-in lever.
What Is a Transmission Control Module
The transmission control module (TCM) is a chip that works with other components to determine when the automatic transmission should switch gears.
The TCM takes into consideration the current RPM, speed, and load placed on the vehicle, so it can accurately shift gears at the most optimal moment.
When you step on the gas hard, the kick-down will make the transmission downshift to give you more power, but otherwise, the gear shifts are oriented towards an economical ride.
The transmission control module should take into consideration uphill and downhill driving and adjust the gears to those situations. On older transmission systems, this is not the case, and the driver must manually shift the gear lever into “3” or “L” gear to prevent unnecessary shifts.
3 Symptoms of a Bad Transmission Control Module
The transmission control module failure is always accompanied by one or more symptoms. By knowing how these symptoms present themselves, it is going to be a lot easier to tell when the TCM needs to be reset or changed.
1. Dashboard Warning Light
The check engine light or the check transmission light is the early sign of transmission control module issues. Often, it will appear before the real symptoms, so you can preemptively address the problem.
The error code can be read directly off the center dash touchscreen on the modern vehicles, but for anything older you’ll need an OBD2 scanner to determine the exact problem.
The scanner will tell you exactly what the issue is, but if it only gives you a code, keep an eye out for P0631, P0700 and P0706 as these are some of the codes related to TCM problems.
2. Hard Shifts
Hard shifts are an unmistakable symptom of a faulty transmission control module. Your Chevy would accelerate normally, but when it’s time to shift gears, it would cause a power delay and a jerk as the gear falls in place.
The symptom may also be caused by the transmission itself, but if you cannot scan, at the very least you can reset the TCM before conducting further investigation.
3. Failure to Shift
The most serious symptom of the transmission control module is failing to shift gears. The transmission may go up a couple of gears normally, only to fail to shift further, even when the RPM is high.
The symptom presents itself mostly on the upshifts, but it’s also possible for it to happen on downshifts, which would cause the engine to stall.
When your transmission reaches this stage, it’s imperative that you diagnose and fix the issue, otherwise you’ll put yourself and the vehicle at risk.
How to Locate the Transmission Control Module
The location of the transmission control module varies between different Chevy models, but on most, it will be located in an easy-to-reach spot.
Lift the hood up and take a look at the area on the driver’s side of the engine bay, just beneath the windshield.
You’ll find a fairly large, metal housing of the transmission control module bolted onto the body, with a large connector cable attached to it.
4l60e Transmission Control Module Location
The 4l60e TCM is a specific module for Chevy, located towards the rear of the transmission case, right behind the cover.
However, on some cars it’s found right next to the engine’s control module, or where you’d usually find a Chevy TCM – underneath the passenger’s side of the engine bay.
The 4l60e was used from 1992 to 2006 with one version update. Before it, Chevy used the 4l60 from 1990 to 1992, and the 700R4 from 1982 to 1989.
How to Reset the Transmission Control Module
Resetting the transmission control module can be done in three ways:
- Disconnect the battery leads.
- Disconnect the transmission control module.
- Follow the reset procedure.
The second method is the most reliable, but it may also be the most complicated if the TCM is located in an inconvenient spot. For that reason, we’ll go through all three methods in detail, and you can try one or all of them to get the desired results.
1. Disconnect the Battery Leads
The simplest solution is to just disconnect the positive and negative terminal of the battery and leave the car for 30 minutes.
The ECU, TCM, and the rest of the electrical components will drain completely, and those without permanent storage will reset.
The trouble is that the transmission control module may have some memory built-in, as some learn from the driver’s habits and adjust transmission accordingly. For those TCM models, this method will not work.
2. Disconnect the Transmission Control Module
Disconnecting the power and data cable from the transmission control module is the most effective way of resetting it.
The first step is to locate the TCM – as explained in the previous section, on most Chevy vehicles it is in the upper driver-side corner of the engine bay.
The transmission control module is connected to a fairly large cable, which is certainly secured in place through a mechanism, so don’t forcefully yank it. First, identify the safety latch – it’s either going to be a lever or a series of plastic or metal clip-on pins.
Before you pull the plug, it’s a good idea to also disconnect the battery, just as a precaution. Pull the cable off the TCM and leave it be for a few minutes. Reconnect the TCM and the battery, then check if the transmission control module is working as expected.
3. Follow the Reset Procedure
The reset procedures are weird most of the time and require you to press the control pedals and turn the key like you’re unlocking a secret code. In reality, these procedures work in the majority of the cases, as they were built-in by the manufacturer to make certain resets easier.
Resetting the transmission control module on a Chevy goes as follows:
- Set the ignition to the “On” position.
- Press the gas pedal all the way down and hold it for 10-15 seconds.
- Turn off the ignition and release the pedal.
- Wait for 1-2 minutes without touching any of the vehicle’s controls.
- Start the vehicle and drive normally, without pushing the engine for about 50-100 shifts.
How to Change the Transmission Control Module
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Changing the transmission control module is just as easy as physically resetting it – there’s only the added step of unscrewing for screws, and mounting them back with the new TCM.
The only thing you need to be careful with is how you handle the new TCM. Think of it more as a delicate computer part than a robust car component.
Even though it has a protective case, it’s still prone to impact and shock damage, so work slowly and carefully.
FAQs
Can I reset my TCM?
Resetting the transmission control module is not only possible but it’s also advised if your vehicle is having transmission issues. Resetting the TCM is a free solution to the problem, as replacing it can cost several hundred dollars.
Will disconnect the battery reset TCM?
On some vehicles, disconnecting the battery is enough to reset the TCM. However, most of the time, the transmission control module’s internal storage will retain the shifting habits and the issue will persist even after the system is drained of power.
To get any TCM to reset, combine the three procedures until it happens: disconnect the battery, disconnect the TCM, and follow the manual TCM reset by turning the key and pressing the gas pedal.
How much does it cost to reprogram a transmission control module?
The reset itself is next to free, and you may only need to pay a trivial cost or tip the mechanic for executing the reset procedure correctly. However, if you’re looking at a TCM change, that can easily set you back $500 or more, as transmission control modules are very expensive.
Does a 4l60e have a TCM?
The 4l60e is in fact the TCM, typically coupled to an E38 or E40 ECM and a Chevy or other GM transmission.
How do I reset TCM 4l60e?
The procedure to reset the 4l60e TCM is identical to the standard Chevy TCM: Set the ignition to “On”, step on the gas pedal, and wait 10 seconds. Release the gas pedal, turn the ignition to “Off”, then wait another minute before starting the vehicle.
What does resetting a transmission control module do?
When you reset the transmission control module, you clear the driving habits it picked up along the way. Say you bought a Chevy V8 from an owner that drove it very slowly – in that case, the car will feel limp even though it should have plenty of power.
By resetting the TCM, you make it start fresh and relearn your driving habits. It’s a very useful step and should be done every couple of years.
What causes a transmission control module to fail?
Aside from physical damage, the most common cause of TCM failure is voltage overload. This could happen for a number of reasons, with aftermarket power consumers being the most likely cause.
How do I reset my transmission light?
The only reason you’d want to reset the transmission light is to clear the warning after solving the underlying problem. It’s never a good idea to get rid of the warning and let the problem build-up.
With that being said, clearing code is very easy – all you need is an OBD2 scanner, which plugs into your vehicle’s diagnostic port. Follow the on-screen instructions to read and clear any of the codes. This will also turn off the dashboard warning lights.
Summary
On most Chevy vehicles, resetting the transmission control module is a simple task because it’s easy to locate if you need to disconnect it.
The reset procedure is also very simple – just a matter of turning the ignition, applying gas, and waiting in the right sequence.
This procedure should work on almost all Chevy TCMs, including the 4L60E.
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