The vehicle comprises so many internal systems that might get damaged at any time. One of the prime components of the vehicle is the TCM or the transmission control module. It generally controls the shifting of the gear and manages the internal transmission components. It also communicates with the PCM to monitor the vehicle’s overall condition. But what if the TCM suddenly fails to operate? How much will it cost to repair the whole TCM? To crack all the answers, I will discuss all the aspects regarding the symptoms, causes, internal mechanisms, and of course, the repairing cost of the TCM. So let us begin the discussion.
What is a transmission control module?
The TCM is a collection of a group of circuit Boards and microprocessors. This is one of the crucial parts of the vehicle system that works harmoniously with the other transmission components of the vehicle. It is a type of the main computer in the vehicle that is responsible for monitoring and maintaining communicating with the other particular Parts of the car and regulating the gear shifting. A TCM is mainly the main controlling unit in the vehicle that also helps to increase the gear and the other transmitting components. It activates the system’s solenoid that initiates the flow of the pressurized hydraulic fuel.
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The PCM activates a decent number of sensors to determine the exact gear ratio. The vehicle’s internal controlling unit generates and operates the vehicle’s speed, shifting, and temperature. The system’s input speed sensor allows TCM to determine the actual rotational speed of the converter of the torque.
Where is the TCM located?
The location of the TCM varies in different car models. In Some cases, TCM is situated inside the transmission next to the valve body or under the center console. Some cars might have the TCM outside the transmission in-line with the wiring harness. Transmission control modules can sometimes even be found inside the gearbox. The TCM can be located anywhere inside the vehicle. If you want to find out its latest location, you might check the manufacturer-specific user manual. 
The Significance of the TCM
The TCM plays a significant role in the internal transmission system of the car. The importance of the TCM is being discussed with specific points,
- It provides an essential link between the transmission system and the engine of the car. The TCM plays a vital role in shifting the gear of the car. The changes in the gear are essential to increase the mileage and overall efficiency of the vehicle.
- The TCM is responsible for maintaining the bondings among the transmission components, And this harmonious composition makes the car even faster and more effortless.
- The TCM improves the gear shifting quality, which expands the gear box’s quality and makes the car even smoother on the road.
- The ability to send the codes to the PCM of the vehicle is another tremendous job of the TCM that reduces the chance of internal damage inside the hood.
How does the TCM work?
The TCM is mainly the main contributor to shifting the gear to the next level. For the shifting, there are many sensors incorporated into the process. Those sensors work combinedly to perform a successful shifting of gear. Let us discuss the sensors,
Vehicle speed sensor
This sensor is mainly responsible for governing the overall speed of the vehicle. It tells the TCM when the gear needs to be shifted and when it has been operated. If this sensor goes bad, then the overall transmission system of the car is destroyed. The VSS also regulates the oil control valve as the fuel is the main factor behind the speed generation. So this is one of the most significant sensors to keep the TCM system on track.
Throttle position sensor
The TPS or the throttle position sensor is very crucial for measuring the overall load in the engine and the system. The engine is the most crucial part of the vehicle. This sensor determines the actual load and pressure onto the engine and the information to the TCM, and then the TCM takes the necessary decision on what gear shift proportion the system needs. And according to the data, it increases or decreases the level of the gear for the vehicle.
Wheel speed sensor
Wheels are most of the time neglected as the most trivial part of a vehicle. But the wheels carry the overall load and pressure of the car. A sensor called the WSS or the Wheel speed sensor controls the direction, rotation of the wheels, the tread depth, the diameter rotation of the wheel, and many more chores related to the wheels. IT plays a vital role in shifting the gear of the vehicle also. Suppose the wheels are stuck during the movement, then the car stops suddenly. The sensor plays an important role in avoiding accidents as the starting and stopping of the vehicle are related to the operation of the wheel.
Transmission fluid temperature sensor
This sensor is solely related to maintaining the transmission system of the vehicle. Sometimes overheating may cause an inconvenience in the system of the TCM. As soon as the TCM detects overheating, it starts to send the notification to the main PCM of the vehicle that monitors the overall system of the car. Whenever the temperature rises in the system, the TFT sensor leaks some coolant to reduce the overall temperature. The car activates the limp mode to avoid the destruction from overheating, which means the car suddenly stops operating. The TCM uses the data from the TFT sensor to operate the torque converter lockup clutch or the line pressure.
Input Speed sensor
It is also called the turbine speed sensor because it is associated with the turbulent rotation of the wheel. This sensor sneaks and calculates the appropriate amount of slippage to incorporate the operation of the transmission clutches, bands, and torque converter clutch. This sensor is also associated with the car’s speed.
Brake light Switch
The brake light switch is one kind of indicator of the gear change to the lower position; the modern vehicle uses this sensor to realize if any downshift is needed when the brake paddle is being pushed. This sensor also helps the TCM figure out the shift lock solenoid, which initiates the braking system’s overall movement.
Traction control system sensor
The traction control system sensor or the TCS gives the TCM a proper signal about the condition of the road, the elevation, the Roughness of the surface, Road surface initiation, etc. This also gives the TCM the proper driving strategy and controls the entire braking and acceleration systems.
The Shifting Solenoids
This tiny plunger-shaped solenoid is incorporated when directing the flow of pressurized hydraulic fluids. The transmission control module conveys the electric charge through the wire then the entire mechanism of the plunger is controlled by it. The shifting solenoid allows or impedes the fuel flow into the passageway.
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Pressure Control Solenoid
The TCM accurately controls the pressure of the system as the automatic transmission needs pressurized hydraulic fluid. The pressure control solenoid may have controlled the clutches or bands, and the failure of the solenoid causes severe damage, shattering, and overheating to the system. In the long run, it may fail the entire transmission procedure.
Torque converter clutch Solenoid
If the TCC solenoid or the Torque converter clutch Solenoid is in a lockup position, both the transmission and the could operate simultaneously. The TCM is solely responsible for operating the TCC.
The condition of ECM
The ECM is called the brain of the vehicle. It mainly controls the overall infusion and operational system of the vehicle. The TCM sends the information regarding any fault to the ECM. The TCM may sneak out the error codes, faults in the Oil control valve, and timing components regarding the rotation of the camshaft position, inadequate gear shifting, and so many other cases inside the car. So the coordination between the PCM and TCM is very important for the car’s smooth operation.
Cruise Control sensor
It is a type of self-sufficient module incorporated with the modifying and shifting behavior of the car to adjust the particular speed. If this module fails to work, severe damage could happen to the vehicle.
What happens when a transmission control module goes bad?
There are so many possible symptoms of a bad transmission control module. I will discuss those symptoms briefly,
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The check engine light illumination
The check engine light may illuminate for several reasons. And those reasons may include a bad
transmission control module or the car’s transmission system. The CEL may get blinking for other causes like a low fuel level, a shattered timing chain, bad sensor and connector issues, short circuits, failure of the solenoids, and many more. But how could you figure out if it is the TCM problem? If the OBD2 scanner flaunts the trouble code P0700, it is a TCM problem.
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Unnatural shifting of the Gears
What happens if the shifting of the gears does not act according to your command? It may initiate a bad accident in your car. This unintended shifting may cause unwanted issues like the driving speed decreases, the fuel consumption increasing quickly, the exhaust may emit bad fumes, and many more other irregularities in the vehicle. This can also affect the braking system in the car. If this unintentional shifting occurs, you must repair the gear as early as possible.
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A distinctive problem in the higher gear position
Normally the gear works quite decently, but the difficulty starts when the gear is shifted at a higher level. The gear stocks suddenly, or the gear is not just capable enough to adjust the level. When this happens, you suddenly notice that the RPM simply keeps increasing. If the gear is intended to operate at the highest level, it should be on the upper level instead of dropping.
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Downshifting problems
This problem is very much familiar to the previous one. When you see a sudden traffic jam, you need to decrease the car’s speed and smash the brake and lower the gear. But you feel that the gear is stuck and cannot be moved at all. That means that you can not reach the downshifting. There are some distinctive causes behind the failure of the downshifting. Figure out those problems and repair the affected part.
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Retarded Shifting
The speed of the car is mainly dependent on the switching between the gears. If it takes a long time to choose between the gear cycles, it may reduce the car’s speed. Suppose you are climbing a steep mountain and you Are trying to shift the gear to the upper position and it is not responding correctly, then you may have to face a severe accident as the car goes backward. The delay in shifting between the gears fails the acceleration system, and you won’t be able to increase the speed according to your expectation.
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Shabby fuel performance
A problem in the TCM can badly affect the car’s fuel performance. This is because the gear has been shifted and is more or less interconnected with the fuel engine. A problem in the gear shifting means it will consume more fuel to operate the car. As a result, the fuel economy decreased badly as well as fuel consumption increased. Issues with the gear shifting make the engine work harder, and as a result, more fuel is exhausted in the process.
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Overheating the Transmission
Overheating is one of the biggest threats to the vehicle. And an overheated TCM is like a death ride for the car. The transmission may be struck, and the overheating may impede the acceleration. The overheating of the TCM affects the fuel economy as the engine has to work more intensively. If the transmission catches up to sudden heat, then you must check and repair the TCM as soon as possible.
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Lower Transmission Fluid
There is a variety of fluids operating inside the car. The fluids, coolants, liquids, and oil combinedly enable the car to run. Among those fluids, the transmission fluid is one of the crucial elements in the TCM. Lower transmission fluid may increase the chance of friction, corrosion, and decaying of the TCM internal parts. The lower level of the transmission fluid reduces the moisture inside the TCM parts, and eventually, ghostly sounds may be produced from the engine.
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Transmission gear slipping
As the transmission gear changes, it initiates the total operation from the very beginning. When you suddenly decrease the gear to the lowest level, it consumes a heavy amount of fuel, and the fuel consumption suddenly increases. The transmission gear may sometimes fall apart, and it may slip. When you encounter the gear slipping, then you must stop the car immediately. Otherwise, it may cause more destruction to the system.
Transmission control module repair cost
The repairing cost of the TCM is around 300$. But this cost may vary depending on different other factors. The cost of the TCM repairing may include the labor cost and the TCM repairing parts cost. The replacement cost is slightly higher than the repairing cost. The cost of repairing can also be higher in some brands of cars. It may fluctuate between 200$ to 750$, including all the tax and VAT. Sometimes the installation of the new TCM may increase the cost even more. Some TCM could not be compatible with the particular brands of the car. In that case, you need to be very keen to adjust the TCM into the main section of the vehicle.
How much would it cost to replace a transmission control module?
There is always an option of replacing the TCM in case it encounters severe damage. The replacement cost of the TCM is slightly higher than the actual repair cost. You need to spend around 600$ to 1000$ to replace the TCM with a brand new one.
Summary
The transmission control module is one of the precious parts of the vehicle. A damaged TCM can cause you a gigantic amount of money to fix the issue, and the TCM regulates the gear shifting and maintains the overall harmony among the other parts of the transmission. The vehicle that is already showing the symptoms of bad TCM must be avoided from driving as that forceful driving may cause great damage to the internal parts of the car. So the key to getting rid of this problem is to take the car to a professional and perform a check-up. I guess that this article proves to be worthy enough to eradicate all the issues regarding the TCM. The cost of the repairing and replacement of the TCM is also discussed in a detailed manner so that you can get An overall idea regarding the fixing of the TCM.
FAQs
Can I drive with a damaged TCM?
Look, it is not wise to drive with a damaged TCM. As a bad TCM may be harmful to the car, The incorrect shifting of the gear may cause devastating harm to the car. It is wise that you must repair or replace the TCM in order to get the maximum fuel mileage. And always avoid driving with a weak and damaged TCM.
How much time does it need to fix a transmission control module?
There is no fixed period of time for the repairing of the TCM. It may take a few days to repair the TCM. It depends on the car model; if your car is rear-wheel drive, then it will take 1 to 2 days to fix the TCM. In the case of a front-wheel-driving car, it may take 3 to 4 days for the reparation.
What is a TCM fuse?
The TCM fuse is one of the central commanding sections of the car that collects data from the transmission parts like the (throttle position sensor, turbine speed sensor, and fluid temperature sensor) and then sends those data to the main PCM. This fuse is also responsible for operating the shifting of the gear.