If you own a GMC (General Motors Company) vehicle, you may have encountered the GMC Check Engine Light. This light is part of the onboard diagnostic system that monitors the emission control system of your car. When the GMC Check Engine Light comes on, it means that there is a potential problem with your car’s engine or related components. Depending on the severity of the issue, the check engine light may be steady or flashing.
In this article, we will explain what the GMC Check Engine Light means, some common causes, and what you should do when it comes on. We will also provide tips for preventing or fixing the GMC Check Engine Light issues.
Common Causes of GMC Check Engine Light
There are many possible reasons why the check engine light might come on in your GMC Check Engine Light vehicle. Some are minor and easy to fix, while others are more serious and require professional service. Here are some of the most common causes of the check engine light:
Loose or faulty gas cap: The cap is a simple but essential part of your car’s pollution control system. It prevents fuel vapors from escaping and polluting the environment. It also keeps the fuel flow steady and prevents dirt and water from entering the gas tank. If the gas cap is broken, lost, or just not there,
it can trigger the check engine light. You need to tighten or replace the gas cap with the right type 1 to fix this issue.
- Poor fuel quality: The fuel quality can affect your car’s performance and emissions. Using contaminated or low-octane energy can cause your GMC Check Engine Light to knock, ping, or misfire. This can damage your engine and catalytic converter over time. It can also turn on the “Check Engine” light. To avoid this issue, you should use high-quality fuel from reputable suppliers1.
- Catalytic converter issues: The catalytic converter is vital to your car’s emission control system. It converts harmful exhaust gases into less harmful ones before they exit the tailpipe. However, the catalytic converter can wear out or clog with material over time, mainly if you use poor-quality fuel or have faulty spark plugs or oxygen sensors. If your car’s catalytic converter is broken or jammed, it may not run well, lose speed, smell bad, and use more gas. It can also make the engine check light flash 12 times.
- Oxygen sensor malfunction: The oxygen sensor is a device that measures the amount of oxygen in the exhaust gas. It sends this information to the engine computer, which adjusts the air-fuel mixture accordingly. Your car can run too rich (with too much fuel) or too lean (with insufficient power) if the oxygen gauge is broken. This can affect your car’s performance, fuel economy, and emissions. It can also damage your catalytic converter and spark plugs. The check engine light can come on if the oxygen monitor is broken.
Mass airflow sensor malfunction: The mass airflow sensor is a device that measures the amount of air entering the engine. It also sends this information to the engine computer, which adjusts the fuel injection accordingly. If your car’s mass airflow gauge is broken, it may run too rich, lean, stop, or pause.
This can affect your car’s performance, fuel economy, and emissions. It can also damage your catalytic converter and oxygen sensor. The check engine light can come on if the mass airflow monitor is broken12.
- Spark plug or ignition problems: The spark plugs make a spark that lights the mixture of air and fuel in the cylinders on fire. The ignition system includes components that deliver electricity to the spark plugs, such as coils, wires, and distributors. If any of these parts are worn out, dirty, or damaged, they can cause your engine to misfire, which means that one or more cylinders are not firing correctly. This can affect your car’s performance, fuel economy, and emissions. It can also damage your catalytic converter and oxygen sensor. Spark plug or ignition problems can cause the check engine light to flash12.
How to Deal With the GMC Check Engine Light
If you see the check engine light come on in your GMC Check Engine Light vehicle, you should not panic or ignore it. Depending on how the light behaves, you should take different actions:
If the GMC Check Engine Light is on steady, it means that there is a minor issue with your car’s emission control system2. You can keep driving for a short distance, like when you move or go to the mechanic. However, it would help if you had your car diagnosed and repaired as soon as possible2. To do this, you can follow these steps:
- Check the fuel cap: Ensure it is tightly secured and not damaged. If it is loose, tighten it and see if the light goes off. If it is damaged, replace it with a new one1.
- Use a scan tool: You can use a scan tool or an OBD-II code reader to read the trouble codes stored on your car’s computer. These codes can help you identify the cause of the GMC Check Engine Light. You can find the meaning of these codes online or in your owner’s manual2.
- Seek professional service: If you cannot fix the issue, take your car to a qualified mechanic for further diagnosis and repair. They can use more advanced tools and equipment to find and fix the problem2. If the GMC Check Engine Light is flashing, it means that there is a severe issue with your car’s emission control system that could damage your engine or catalytic converter2. You should stop driving as soon as possible and turn off the engine2. To do this, you can follow these steps:
- Stop the car in a safe place: Find a safe place to park your car, like a side or a parking lot. Avoid driving on highways or busy roads2.
- Use a scan tool: You can use a scan tool or an OBD-II code reader to read the trouble codes stored on your car’s computer. These codes can help you identify the cause of the check engine light. You can find the meaning of these codes online or in your owner’s manual2.
- Call for roadside assistance: If you cannot drive your car safely, call for roadside assistance or towing service. Do not try to take your vehicle to a repair shop, as it could cause more damage to your engine or catalytic converter2.
The check engine light tells you a lot about the health and emissions of your car.
When it comes on, it means something is wrong with your car’s engine or related components. It would help if you did not ignore or put off fixing this problem, as it could lead to bigger problems and more expensive fixes.
Some common causes of the GMC Check Engine Light are loose or faulty gas cap, poor fuel quality, catalytic converter issues, oxygen sensor malfunction, mass airflow sensor malfunction, and spark plug or ignition problems. Depending on how the light behaves, you should take different actions. If the light is on steady, you can continue driving for a short distance, but you should have your car diagnosed and repaired as soon as possible. If the light flashes, stop driving immediately and call roadside assistance.
To prevent or fix the check engine light issues, use high-quality fuel, maintain your car regularly, replace worn-out or damaged parts, and follow your owner’s manual recommendations.
We hope this article has helped you understand what the check engine light means, some common causes, and what you should do when it comes on. If you have any questions or need further assistance, please contact us at AutoNation GMC Check Engine Light Mendenhall or Dash Lights Advisor. We are happy to help you with your GMC vehicle needs.