Can a Bad Throttle Body Cause Transmission Problems?

A car is a complicated piece of work. With so many components to it, they all link together to create an engine that runs smoothly. This includes the hydraulic pump, gears, clutches, brakes, and more. But can a bad throttle body cause transmission problems? 

What is a Throttle Body?

A throttle body in a car is used to maintain and control how much air is allowed into the engine. You can compare it to a butterfly valve. You can find this between the air cleaner and the intake manifold.  

It is generally made from aluminum. When the driver puts pressure on the pedal, input data is collected. As more fuel is allowed to enter the engine, better combustion and acceleration power is granted as more air enters in. 

What are Signs of a Bad Throttle Body?

If you have a throttle body that is failing, there are several signals you can see. If you notice any of these symptoms, you will want to get them taken care of as soon as possible. Putting this off may lead to larger problems that are more costly. 

Check Engine Light

It is a no-brainer that when the check engine light comes on, something is wrong. It can be difficult to tell, but if there are other signs, it can help you find out what is wrong.

During the internal combustion process, the throttle body plays a huge role. Should it go bad, you will find the car has a weak performance. There could be rough acceleration. As the ECU determines this, the check engine light will pop on. 

No Acceleration

If your throttle body is faulty, you will most likely experience poor acceleration. You may find it to have jerky movements, or hesitates. Or it could accelerate, but has very little power. 

On the flip side, you may find yourself driving down the road, and your car starts to accelerate itself. This is very scary and downright dangerous. 

Either of these signs could be a bad throttle body. The ECU will not be able to allow the engine to work correctly. 


If the air and fuel mixture is wrong in your vehicle, a misfire will occur. It can happen if there is a weak spark plug too. If you have a bad throttle, your air and fuel mix will be off. When you rev up your engine, a misfire will sound like a small bump. 

Rough Idling

A bad throttle body can cause your vehicle to have rough idling. When the car is idling after starting it up, your car should have 600-900 RPM. Any RPM above or below this is cause for concern. If this happens, and there is at least one other sign on this list, chances are the throttle body is bad. 

Fuel Consumption Change

If you have noticed a change in your fuel consumption, you could have a faulty throttle body. In some cases, you may be filling up more. But other times, it could allow you to fill up less frequently. While you and your pocketbook may like this idea, your engine will not. 

Throttle Body Cleaning

If the throttle body does get dirty, your transmission will not run as smoothly as it could. But you can easily remove dirt and grime with one of the many cleaners that are on the market. Frequent cleaning of the throttle body will ensure that it stays clean so your transmission can have optimal performance. 

Signs that your throttle body needs to be cleaned include stalling, poor fuel economy, sluggish engines, and rough idling. 

There are a variety of throttle body cleaning products available for purchase. Most of these are fairly inexpensive, and you can find them for under $10 a can. Most of them are very potent and volatile. It is a matter of personal preference on which one you pick.

Some of these sprays are designed to break up residues and carbon deposits while others will dissolve any deposits that will harm how well your car is performing. Before picking a cleaning product, make sure it is safe for the make and model of your car. 

No matter what product you decide to use, you need to wear gloves and protective eyewear to protect yourself. And you will want to be certain you follow all directions listed on the product.

The fumes can be harmful and the products themselves can irritate the skin. Never smoke while cleaning the throttle body, and be certain you are in an open area. 

We also recommend that before starting this or any cleaning process, you disconnect the ground terminal.

If you have any concerns while cleaning the throttle body, be sure to contact your mechanic or dealership. 

Resetting Throttle Position Sensor

If you need to reset your throttle position sensor or have to install a new one, you will need to follow one of these:

● Begin by unhooking the negative cable from your battery. This can be done for up to 5 minutes. 

● Remove the fuse for your engine control module. 

Is It Worth It to Repair

Depending on the shape of your car will depend on if it is worth replacing the throttle body. If you have an older car that has many miles on it and does not anticipate keeping it for much longer, you may wish to just sell the car as is. 

But if you have a newer car that does not have a lot of miles on it, it is wise to invest some money into fixing the throttle body.

In Conclusion

A bad throttle body will cause your transmission to have problems. You may see rough idling, a change in fuel consumption, misfires, no acceleration, or the check engine light may come on.

If you notice any of these, take heed and clean your throttle body. And if you are not certain how to do that, or if that is even the issue, make an appointment with a mechanic to have it checked over. 

  • Eric Williams

    I'm the founder of Daily Car Tips. I wrote articles in the automotive industry for more than 10 years, published in USA and Europe. I love sharing my knowledge and insights with fellow enthusiasts. Join me on this journey as we explore the exciting world of cars together!