Throttle Control Warning Light (ETC) – Symptoms & Info

Almost all cars after 1990 were equipped with some kind of electronic computer that was supposed to control the functions of the car.

This computer is called an ECU or PCM and is included with every car you buy. In addition to an ECU, there are many other small electronic components such as an Electronic Throttle Control (ETC). ETC has a very important function to perform.

In older cars, the throttle position was determined by a cable that opened the throttle depending on how hard you pressed the accelerator pedal.

However, a direct connection between the throttle valve and the accelerator pedal was not efficient. The car owners experienced increased fuel consumption. Therefore the throttle control unit was developed.

What is the ETC Valve?

This unit makes an important decision every second you drive your car. The ETC collects information from the accelerator and then from the engine to decide how far to open the throttle.

When you press the pedal, an electronic signal is transmitted to the ETC that causes the throttle to open or close wide. If you drive fast and press the pedal fully down, your car’s ETC will detect the situation and keep the throttle wide open to let in the maximum amount of air.

Alternatively, the throttle valve will open slightly if you are only driving to keep the air-fuel mixture at the optimum level.

The throttle control unit is necessary to ensure that you get the optimum amount of power from your engine. If it fails, you will face countless problems in your daily driving. That’s why the ETC light in your dashboard illuminates when problems occur.

This light indicates that there is a problem with the ETC and you should have it checked as soon as possible. The ETC light is normally the last warning you will receive before your engine performance is affected. This is something you can’t afford, so we have made a list of symptoms associated with ETC failure.

Problems Associated with The Electronic Throttle Control

There are a variety of problems that can arise in an ETC. The good thing is that each problem has its own specific code. If something goes wrong, the ECM or ECU triggers the fault code, which causes the ETC to light up in your dashboard.

As soon as the light comes on, you should see a mechanic. The mechanic will attach an OBD2 scanner to your car and check the fault code. This code will tell the mechanic exactly what the problem is. Once he has learned of the problem, the mechanic can make the necessary repairs and delete the code from the system to turn off the fault light.

If you know the associated symptoms, you can make the diagnosis yourself without spending money on a mechanic.

1. Non-Responsive Throttle

The first sign of a failure of the throttle control is a non-responsive throttle. This occurs when you press the throttle but do not get a quick response in terms of faster acceleration. You will feel a weak throttle response and sometimes a tremor before your car accelerates.

One possibility that may occur is if the ETC does not receive proper electronic signals from the accelerator. The ETC will only work properly if it receives correct signals. It is possible that a relay is defective or a wire has come loose from the ETC. Whatever the problem, you will inevitably lose throttle response.

In the worst case, you may not get any throttle response at all, which will cause your car to stop in the middle of the road. Once this happens, you should contact your nearest certified mechanic who has the necessary expertise to deal with such a situation. If you are a DIY mechanic, you can even take a look at the throttle unit to see if there are problems with the throttle wiring or the throttle position sensor.

2. Hesitating Throttle

If the ETC is damaged for any reason, the throttle control light in your dashboard will illuminate. A damaged ETC sends incorrect signals to the throttle position sensor and your throttle will behave incorrectly. This hesitation is slight at first, but increases until a time comes when the accelerator is no longer responding to the throttle at all.

In addition, a hesitant throttle response poses a safety risk to you and other road users. You could be involved in an accident and damage property or lives. To be on the safe side, you should consult your mechanic at the first sign of failure.

3. Poor Fuel Economy

If the ETC light in your dashboard is flashing, it is possible that the mileage of your vehicle is affected. Conversely, poor fuel economy may also mean that either your TP sensor is not operating in accordance with the standards or your ETC light is about to fail.

You may feel that you visit the service station more often. This is because an irregular throttle valve disturbs the air-fuel mixture to such an extent that you sometimes burn more fuel than necessary. A rich fuel-air mixture can seriously damage your fuel economy and make it expensive for you to drive around in your car every day.

4. Limited Acceleration

When things get serious about ETC, you might not only see a throttle indicator light come on in the dashboard but also feel that you can’t accelerate your car more than up to a certain point. This situation is intentional and is done by the ETC to protect the engine from damage. This is called “limp” mode, a safe mode to protect the internal parts of the engine.

Replacement Cost

The ETC is an expensive engine component, and as it is electronic, its cost is sometimes non-negotiable. In most cases, you don’t need to change the ETC, but if you do, you can expect to spend more than $200 – $300, and that too depends on the make and model of your car.

Magnus Sellén

Hello I'm Magnus, the owner and the writer of this website. I have been working with cars since I was 16 and I'm specialized with in-depth Automotive diagnostics. Also been driving drifting for the last 6 years. I'm here to give you answers to all your automotive questions and I hope that you enjoy our content.

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