In automatic vehicles, the transmission control module (TCM), sometimes also referred to as the transmission control unit (TCU), is a computer-like device that controls the performance of the transmission.
The transmission control module works closely with the engine control module (ECM), the devices exchange signals that provide instructions for the performance of your vehicle. The engine control module sends data to the transmission control module, which allows it to compute when to change gears and change speeds for optimum performance.
The TCM takes input data from various switches and sensors in your car, such as those monitoring the positions of the gas and brake pedals, the transmission input and output speeds, gear selection, engine torque and speed, oil temperature and wheel speed. TCM Parking Solutions Download our brouchure. We are a rapidly expanding Independent Parking Committee Approved Operator operated by a dedicated team of car park sector professionals with over 60 years of frontline experience with a structure in place to manage nationwide contracts. Action Racing’s XD Falcon is unloaded Touring Car Masters competitor and tow truck driver Marcus Zukanovic was forced to improvise when his team’s transporter was damaged in shipping after Boost. In most cars, the Powertrain Control Module contains the ECM and TCM in one unit. By combining them, the PCM can better regulate their functions together. For example, when the PCM changes gears, it can pull back the throttle to shift smoother. Your vehicle’s Transmission Control Module is a vital component of any road-going vehicle that runs on an automatic transmission system. Most modern automobiles come with a TCM unit, which is handy compared to relying on mechanical or hydraulic control.
The proper function of the transmission control module is essential to maintaining a vehicle’s gear settings, fuel economy, and emission controls. In some cases, TCMs can become worn out and result in sub-par performance of your car.
Generally, symptoms of a bad TCM are easy to identify if you know what to look for. If your car is experiencing one or more of the signs below, you might need to replace your TCM.
Problems Shifting
Automatic transmissions rely on the transmission control module to signal when to shift of gears. A bad TCM can result in random shifting between gears, shifting to neutral on its own or getting stuck in neutral. If you are experiencing this issue, your vehicle is not safe to drive, and you’ll likely need to have your module replaced.
Poor Performance
If you notice that your car is not correctly picking up speed, or is struggling to go uphill, you may have a bad TCM. Your car’s speed depends on your gears cycling at the right time. If your TCM is faulty, then it may cycle through gears too quickly or too slowly which will negatively impact your car’s ability to accelerate properly.
Bad Fuel Economy
Poor efficiency in shifting will result in reduced fuel economy. A faulty TCM will require your vehicle to work harder to move uphill, or across rough terrain causing you to burn more fuel in the process. If you’ve noticed that your car is burning fuel faster than usual, it won’t hurt to get your TCM inspected by a mechanic.
Driving with a bad TCM is not recommended, it will usually handicap your vehicle or leave it functional in only two gears. Check for any mechanical reasons for the symptoms you’re experiencing before you decide to repair or replace your TCM.
In many cases, problems with the TCM are caused by a burnt circuit or a faulty resistor or transistor. In this case, an experienced mechanic should be able to diagnose the problem and repair the faulty part. In some advanced cases, it may be necessary to replace the entire TCU module.
When troubleshooting your TCM, it is highly encouraged to seek consultation from a mechanic or professional technician. Improper handling of the procedure can result in personal injury or damage to the TCM or your vehicle.
Sometimes, problems with your TCM can be resolved by cleaning and draining the module. You’ll need your car manual to be able to locate and remove the TCM for this procedure. This will require some advanced car repair knowledge and is not recommended for individuals without previous auto troubleshooting experience.
If the above troubleshooting method fails to resolve your TCM issue, you should consider working with a professional to have your TCM replaced.
Thankfully, problems with the transmission control module are not very common and typically appear in older cars with 75,000 or more miles. However, if you find yourself needing to replace your TCM, it can get a bit costly.
RepairPal reports that a TCM replacement will generally range from $600-$700 depending on several factors. Part costs will constitute of the majority of the cost of a repair, while labor costs are estimated between $87 and $111 excluding taxes and fees.
Solo PCMS is an industry leader in the replacement of ECUs, PCMs, TCMs and ECMs. Our remanufactured auto computers come with a lifetime warranty and can help consumers save up to 80% on repair or replacement. Get in touch with one of our expert technicians today and get back on the road in no time