Can a Bad Throttle Body Cause Transmission Problems?

Can a Bad Throttle Body Cause Transmission Problems

The throttle body is one of those vehicle components that not a whole lot of people think about. We suppose because unless you have a bit of knowledge of vehicles, you probably have no clue that it exists.

We don’t blame you. It is an important component, but it isn’t one that regularly fails.

But, what if that throttle body does fail? Is it going to start causing issues for your vehicle? More importantly, is it going to have an impact on the transmission of your vehicle?

Well, that’s what we are going to take a look at on this page.

What Is The Throttle Body?

First things first, what is a throttle body?

Well, a throttle body is a small component in the engine. You can think of it as being like a valve.

The job of the throttle body is to either let air into the engine or keep it out. By carefully controlling the amount of air flowing into the engine, the performance of the vehicle is impacted.

A good amount of oxygen will ensure that your vehicle has a bit more power behind it, acceleration is a lot smoother, and, hopefully, you will get a good amount of fuel economy.

Because the throttle body is a very simple component, it isn’t one that fails all that much. However, when it does fail, you can bet your bottom dollar that you will start to see its impact of it.

We will come to that shortly, though. 

Read also >> Does Cleaning Throttle Body Make a Difference? (Easy Explained!)

Can a Bad Throttle Body Cause Transmission Problems?

Yes, but only if you have an automatic transmission in your vehicle. 

One thing that we didn’t mention in the previous section is that the throttle body has a sensor connected to it. This is known as the throttle position sensor.

It is sending a whole host of information into your vehicle’s computer, particularly if you have a vehicle that has an automatic transmission on it.

The problem is that if you have a bad throttle body, the throttle position sensor is going to be thrown out of sync.

This means that it is going to be feeding back incorrect information to your vehicle, and this can cause the automatic transmission to get the wrong idea about when to switch gears, and sometimes the wrong information about which gears to switch to.

The good news is that if you have a manual transmission in your body, then there are probably not going to be any transmission problems with the throttle body.

There may be a few other issues in your vehicle due to the bad throttle body, but nothing that you will need to worry too much about.

Although, we are eager to point out that there is some debate in the automotive industry right now about whether electric throttle bodies pair well with a manual system, although this isn’t anything that you are going to need to worry about, and it certainly isn’t a problem that you are going to be able to fix yourself anyway. 

How Do You Know You Have a Bad Throttle Body Causing Transmission Problems?

Of course, there are a ton of things that can cause a bad transmission in your vehicle. It doesn’t have to be a bad throttle body.

In fact, chances are that it probably isn’t a bad throttle body. We will tell you a little bit about checking that shortly. However, for now, let’s go through some of the signs that the throttle body is causing your transmission woes.

Although, we do want to stress that each and every one of the issues that we highlight here can be caused by a whole gaggle of things in your vehicle. Remember, your vehicle is incredibly complicated.

If you don’t have experience with the maintenance of vehicles, then we suggest that you head to a garage if any one of these issues decides to rear its ugly head.

Check Engine Light

Yes. That dreaded check engine light. Nobody likes it. Not only does it symbolize that there is an issue somewhere in your system, but the light isn’t going to tell you what the issue is.

You can think of the check engine light as a little bit of a prompt for you to get to your local garage to get your vehicle inspected.

This is the only way to know for sure what is causing your issues (remember, it doesn’t necessarily have to be a bad throttle body!)

Gears Not Switching At The Right Time

As you drive your vehicle, you will start to get a feel for when your automatic transmission should be switching gears for you.

Other than the check engine light, one of the first signs that you will have is that the gear shifting appears to be a little bit off.

The vehicle doesn’t drive ‘right’. It is tough to explain, but it is something that is going to be very noticeable once you are familiar with the way that your vehicle works.

Transmission Slippage

If you notice that your transmission is slipping every so often, then there is a good chance that you have an issue with the throttle body. It is not the only reason why a transmission could slip, but it is a good one.

This is all thanks to the sensors on the transmission body that are sending incorrect signals.

Sometimes, when the wrong signals are being sent, the mixture of fuel and oxygen gets a little bit messed up which, ultimately, leads to that slipping. 

Poor Fuel Economy

Obviously, this has nothing to do with your transmission. Although, we suppose it can be slightly linked. Issues with the transmission (i.e. being in the wrong gears at the wrong time), can lead to you spending more fuel than you should be spending which, ultimately, is going to start causing you a multitude of issues.

If you notice that you are burning through more gas than ever before, then you may want to look at the throttle body.

No Acceleration

Remember what we said earlier? One of the jobs of the throttle body is to allow oxygen to get into the engine. Just the right amount of oxygen. If the throttle body is clogged or damaged, then the acceleration will be poorer.

You may find that the vehicle doesn’t quite have the power that it should do. This could lead to even more issues with transmission switching i.e. the vehicle may shift down a gear when it shouldn’t down when it shouldn’t do.

Misfiring Of Your Vehicle

Is your vehicle misfiring when you start it? That is pretty much a huge sign that you have an issue with the throttle body.

When your vehicle misfires, it is almost certainly down to a poor mixture of oxygen and fuel in the engine, normally less oxygen than there should be.

Frequent Stalling 

This can be related to your transmission. If you have a bad throttle body, then you may find that the vehicle stalls a little bit more frequently.

This is due to issues with the transmission shift.

Rough Idle 

If your idle RPM is higher or lower than normal (generally between 600-900 RPM), then you have a rough idle. This is almost certainly down to a bad throttle body.

How Do You Fix a Bad Throttle Body?

Pretty much the only thing that you are going to be able to do yourself is clean out a dirty throttle body.

Most transmission issues are due to the throttle body getting a little bit clogged. 

If you flick through the manual for your vehicle, then it will tell you exactly where the throttle body is. Normally, you can take it out and wipe it clean.

As long as you have been properly maintaining your vehicle, then the job is going to be fairly quick.

Sadly, if the issue with the throttle body is down to damaged sensors and the like, or perhaps the throttle body has physically broken, then there is not much that you can do other than take your vehicle in to be repaired.

You can head to any garage for the job to be carried out. It is normally a quick and easy repair, assuming that the sensors are not damaged.



A bad throttle body can cause issues with your transmission. Although, do bear in mind that there are a ton of issues that can lead to transmission issues.

So, if you have a bad transmission, do not automatically assume that the throttle body is at fault. Although, you can double-check the throttle body to make sure that it isn’t clogged.

Remember, if you do have transmission issues, then they need to be sorted out almost immediately. A bad transmission is not only going to lead to poor fuel economy in your vehicle, but it is downright dangerous to drive your vehicle with a bad transmission.

Take your vehicle to a garage as soon as you notice any issues with it. 


Steve P.

Steve is an automotive technician, technical writer, and Managing Editor. He has held a lifelong passion for cars, with a particular interest in cars like the Buick Riviera. Steve is based in Boise, Idaho.

Recent Posts

error: Content is protected !!