Electronic Throttle Control Light: Causes and Symptoms

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The electronic throttle control light is a unique light that most people won’t experience. As a result, many people won’t know what to do or if it’s dangerous or not.

Just to be clear, the symbol is a lighting bolt between inverted parenthesis. Don’t worry if this light is on your dashboard; I’m here to help.

In this post, I will go over everything you need to know about the electronic throttle and the warning light on your dashboard.

Let’s get started.

What Is The Electronic Throttle Control?

The electronic throttle control is an electronic connection that connects the gas pedal to the throttle. This is a relatively new technology that only became standard in the last 4o years. Older cars used direct linkages or wires to connect the gas pedal and the throttle.

Today the electric throttle plays an important role and works with the ECU to incorporate many new features. For example, thanks to the electronic throttle, new vehicles now have cruise control, traction control, stability control, torque management, and fuel supply.

These new features are now possible because the throttle can be electronically controlled without relying on the acceleration pedal.

What Does the Electronic Throttle Control light Look Like?

electronic throttle control warning light

The electronic throttle control light is lightning bolt between inverted parenthesis or  brackets. The dashboard light can vary slightly depending on the make and model of the car you drive. In some cases, the light might be orange and it may use brackets instead or parenthesis. 

This light is typically in yellow and located near the check engine light. 

On newer vehicles the light will likely appear at the center of your dashboard or center console. 

What Causes the Electronic Throttle Light To Turn On?

The electronic throttle has a very specific function in your car. Many things can cause it to fail and for that dreaded warning light to illuminate your dashboard.
Some common reasons cause the electronic throttle to fail, and these are listed below.

1. Faulty Throttle Control Sensor

One of the most common reasons that an electronic throttle control goes bad is when the sensor fails. This sensor tells the ECU the position of the throttle control.

The ECU then uses this information to tell the throttle control either to open or close. When this sensor is not working, the ECU won’t be able to communicate the correct message to the electronic throttle control.

This can cause the throttle to remain close or open when it should be doing the opposite. This can cause a timing issue, and as a result, your engine will be running on a suboptimal fuel mixture.

The exact reason for a failing sensor can vary. This includes physical damage, a faulty relay, or an electrical short.

2. Faulty Accelerator Pedal Position and Module Sensor

The introduction of computer-based cars also introduced many more sensors and relays into most vehicles. Another crucial sensor in the electronic throttle control is the accelerate and module sensor. This sensor tells the ECU the position of the gas pedal. The ECU uses this information to tell the electronic throttle control when it should open and close.

When the accelerator position sensor is not working properly, this can cause issues with your electronic throttle. This miscommunication will cause the electronic throttle control to open and close at the wrong times or stop working altogether.

The electronic throttle relies on this information to determine when it’s going to open and close. When the accelerator position sensor becomes faulty, this will likely trigger the electronic throttle control warning light to turn on as well.

3. Stuck Throttle Body

This is one of the most common reasons an electronic throttle will stop working properly. This is because the throttle body can either get stuck open or closed.

The reason it gets stuck can vary drastically, which can make it hard to diagnose. But when the throttle body gets stuck in one position, this will cause one of two problems. The engine will either get too much air or not enough air inside the fuel mixture.

This can lead to a variety of problems inside your engine and with your vehicle.

4. Dirt and Grime Inside the Electronic Throttle

Another common reason that the electronic throttle control light will turn on is when the throttle body is dirty or clogged.

Typically, over time the electronic throttle can become dirty. If there is dirty, grime, or other material trapped inside the electronic throttle, this can cause issues.

This dirt and grime will make it more difficult for air to pass through. In extreme cases, the dirt and grime can cause the throttle valve to stop opening.

5. Wear and Tear To the Electronic Throttle

Wear and tear can happen over time. Often, the parts inside the throttle will become worn down due to dirt, grime, and other contaminants.

Another common issue is direct damage to the electronic throttle control. The exterior of the throttle has many plastic parts. Just beneath these plastic parts, you will find gears, sensors, and the throttle engine.

If any of these parts get damaged, it can cause your throttle to stop working correctly. Since all these parts rely on one another to work when one gets slightly damaged, it can still result in a total electronic throttle failure.

Symptoms of a Faulty Electronic Throttle Control

A common sign of a faulty electronic throttle control is the warning light. This light does not always turn on, but this doesn’t mean you can identify when you have an electronic throttle control issue. You can look out for several symptoms to help you determine if you’re having issues with faulty electronic throttle control.

You can also use these symptoms to help you determine if your electronic throttle issues are becoming progressively worse.

1. Reduced Fuel Economy

A common sign of a faulty electronic throttle control is reduced economy. Your fuel economy is affected because the electronic throttle controls the amount of air entering the engine.

When this is not working properly, your engine will not be running with the optimal air to fuel ratio. When this happens, you will experience reduced fuel efficiency.

The electronic throttle control also disrupts the timing of the combustion engine. When air doesn’t reach the engine at the correct time, this can also reduce fuel economy.

Measuring Your Fuel Economy

It’s often hard to measure fuel economy if you’re not paying attention.

An easy way to determine if you are experiencing reduced gas mileage is if you’re refilling your tank more frequently.

This is especially easy to measure if you follow the same commute every day.

Let’s say you refill your tank every Monday. If all of a sudden you need to refill on Saturday, then this might be a sign of reduced gas mileage.

In newer vehicles, the gas mileage is displayed on your dashboard or the central display. Keep track of this value over several weeks.

You can compare your MPG to the MPG recommended for your car’s specific year and model.

An easy way to determine your vehicle’s average gas mileage is using the U.S Department of Energy’s fuel economy website.

If your car does not display the MPG on the dashboard, you can use an app to track your MPG.

If your car has a lower MPG than the recommended MPG for your vehicle, I suggest you have your vehicle inspected by a professional mechanic.

2. Reduced Acceleration

Another common symptom of a faulty electric throttle is reduced acceleration.

Often times your car will not accelerate as fast as it did before. This is typically more apparent when you are trying to accelerate fast. If you plan to test this make sure you do it in a safe area with no people, cars, or other objects around.

When you push down your gas pedal, you are likely to feel a weak pull than the jerk that you would normally feel.

This happens because the electric throttle is disrupting the timing and fuel mixture inside your engine. This will cause a delay and ineffective engine performance.

3. High or Rough Idle

A faulty electric throttle can also cause your engine to have a high or rough idle. High idle and rough idle are slightly different, but the same thing typically causes them.

First, a high idle is when your car is excessively loud when in idle. With high idle, your car might be louder than it normally is when you turn it on or when it’s idle.

Rough idle will cause your car to shake excessively, which you can typically feel on the steering wheel.

This typically happens when the electric throttle control gets stuck open. This will cause too much air to enter your engine. This is what causes your engine to run experience rough idle.

4. Sputtering Engine

Another common symptom of a failing electric throttle is a sputtering engine. The main reason your engine will sputter is that the fuel mixture has too much air.

This is likely to happen when the throttle gets stuck open. The additional air will cause your engine not to have sufficient fuel for the engine to run smoothly. Engine sputtering is directly related to the fuel system.

If the issue is not associated with your electric throttle, then you likely have an issue with your fuel system. Some common culprits include the fuel pump, fuel filter, or fuel injectors.

5. Inconsistent Throttle Performance

An obvious but overlooked symptom of a failing electric throttle is inconsistent throttle performance. This typically includes excessive acceleration or lack of acceleration.

Inconsistent throttle performance can be described as acceleration that does not match with pedal pressure. For example, you might push on the gas pedal and only experience minor acceleration. Likewise, a gentle push on the gas pedal might cause a jerk in your vehicle.

The reason for this is that the electric throttle and the throttle valve are not working in unison. This is what causes the inconsistent throttle performance.

How Much Does It Cost To Repair The Electronic Throttle Control?

The price to repair an electronic throttle control can range between $175 and $600. For most people, you can expect to spend around $275 and $400. The cost of repairing older vehicles will be on the lower end, and newer and more expensive cars will be higher.

The cost of labor to repair or replace the electronic control is between $100 and $300. In most cases, the repair can take between one and two hours, and depend on the final price will depend on the rate of your mechanic.

The electronic throttle control body will cost between $75 and $300. The make and model of your vehicle will determine the overall cost of your electronic throttle. The basic stock replacement generally costs between $70 and $150.

The cost to replace the electronic throttle on newer models is typically less expensive than on older models. Likewise, luxury cars or larger cars typically have more expensive electronic throttle bodies. For example, a replacement BMW electronic throttle costs approximately $250, while a Honda’s electronic throttle costs around $100.

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