How To Reset Service Engine Soon Light 1990 To 2002 Chevy Tahoe

If the Service Engine Soon light on your 1990 to 2002 Chevy Tahoe comes on, it means that some of the vehicle’s components have failed and need to be replaced.

In this article, we will show you how to reset the Service Engine Soon light on your 1990 to 2002 Chevy Tahoe.

What Does Service Engine Soon Light Means?

The “service engine soon” (SES) light on older vehicles is an indication that the vehicle’s onboard diagnostic system has detected a problem. The SES light may also be referred to as a “check engine” light.

When the SES light is illuminated, it means that the vehicle’s emission control system is not working properly and needs to be serviced. Depending on the severity of the problem, the SES light may be either yellow or red. If the SES light is yellow, it means that the problem is minor and does not need to be addressed immediately.

However, if the SES light is red, it means that the problem is more serious and should be addressed as soon as possible. Ignoring the SES light can result in increased emissions, reduced fuel economy, and even damage to the engine.

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The reason why older vehicles had so few warning lights is that they had fewer sensors. A service engine soon lights covered a lot of problems. The only way you can diagnose an issue on an older vehicle is by scanning it.

Modern vehicles are equipped with more sensors and electronics than ever before. Each of these components has its own little light that can come on to indicate a problem.

OBD ports are typically located under the dashboard on the driver’s side of the vehicle. They are used to connect diagnostic tools to the vehicle’s computer system in order to diagnose and repair problems. Some newer vehicles have OBD ports that are hidden behind a cover, while others have them in plain sight.

There are a lot of scanning tools on the market that range from $50 to $1000. But, for scanning your own vehicle, you don’t need a fancy scanning tool. You can get a cheap one and scan it.

How To Reset Service Engine Soon Light 1990 To 2002 Chevy Tahoe

How To Reset Service Engine Soon Light 1990 To 2002 Chevy Tahoe

A lot of times, the reset service engine soon light is illuminated when you need to repair something on your 1990 to 2002 Chevy Tahoe. Since a lot of issues can trigger the service engine soon light, you will need to scan your vehicle to find the issue. So, we will start from there and move towards resetting the service engine soon light.

1. Scan your vehicle for possible malfunctions

How To Reset Service Engine Soon Light 1990 To 2002 Chevy Tahoe

The reset service engine soon light doesn’t illuminate for no reason. It means that the vehicle’s diagnostic system has found a malfunctioning part that needs repairing. Since we are working on an older vehicle, the service engine soon light covers a lot of parts. This is why it’s important that we scan the vehicle in order to pinpoint the issue.

Plug the scanning tool in the OBD port located underneath the steering wheel. This OBD port is connected to the vehicle’s computer. Any problem that the vehicle’s computer has picked up, will show it on the scanning tool.

2. Replace the malfunctioning part

The service engine soon light can illuminate for a lot of reasons. But in all cases, it means that some kind of repairs has to be done to the vehicle. Only deleting the trouble codes without fixing the actual problem will trigger the same code after a few minutes.

The most common reasons why a service engine light illuminates on a dashboard are:

  • Scheduled Service. By schedule service, I mean scheduled oil change or other fluids. This also goes for maintenance items like an air filter, fuel filter, etc.
  • O2 (oxygen) Sensor Failure. The engine is equipped with a lot of sensors including a mass airflow sensor, engine speed sensor, spark knock sensor, the O2 sensor, and more. The Oxygen sensor monitors how much oxygen exits the vehicle and determines if the combustion was efficient (correct air to fuel ratio). When the O2 sensor malfunctions, the service engine soon light will come up.
  • Spark Plugs Need Replacing. Spark plugs have a lifespan of about 30,000 to 100,000 miles, depending on the material they are made out of. When they go bad, it can cause a lack of acceleration, misfiring, hard starts, rough idle, and an illuminated service engine soon light.
  • Faulty Catalytic Converter. The catalytic converter has the purpose of filtering out the exhaust gases and making them less harmful. Dealing with exhaust gasses constantly takes a toll on the catalytic converter which fails eventually. A faulty catalytic converter will trigger the service engine soon light.

By scanning your vehicle, you are going to be able to determine the exact problem and fix it. However, even if you fix the issue, the vehicle’s computer has to be reset. Otherwise, it will again show the service engine light soon.

3. Reset the service engine soon light

Once you have fixed the actual problem with the vehicle that triggered the service engine soon light in the first place, it is time to reset the computer. In order to reset the vehicle’s computer, you will need to disconnect the vehicle’s battery. First, disconnect the negative terminal and then the positive. Leave the vehicle like this for about five minutes.

The vehicle’s computer has capacitors in it to hold a charge for about three minutes. That’s why we are going to wait for about five minutes so the capacitors release the energy inside them and don’t store any information that we had before.

During the five minutes, the vehicle’s computer will reset and go back to factory mode. Meaning, that the next time you start your vehicle, your vehicle’s computer will detect that you have fixed the problem and won’t ignite the service engine soon light. This is a great way to reset the service engine light without any fancy scanning tools.

If the service engine soon light comes on after driving for about fifty to a hundred miles, it means that your vehicle has another problem. Then, you will need to scan the vehicle again for trouble codes and repair the problem.

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Hi there. I am a certified Automotive Service Excellence (ASE) mechanic since 2018 and a car detailer for 10 years.

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