The appearance of the check engine light on your GMC dashboard left you concerned, right? But in many cases, it signals a relatively minor issue that can be resolved with a few simple steps.
This article will help you understand the causes of why the check engine light comes on, and guide you in diagnosing and addressing the problem.
What Does It Mean When GMC Check Engine Light Comes on?
In any GMC model, the check engine light illuminates when the onboard diagnostic system detects a potential issue with the emission control system.
A steady check engine light indicates minor issues such as a loose fuel cap or poor fuel quality.
If the check engine light is flashing, your car might be experiencing trouble with a misfiring engine or catalytic converter issues. To prevent further damage, be aware of this light and promptly seek service.
Can I Still Drive With the Check Engine Light?
Yes, in most cases, if the check engine light comes on and your vehicle seems to be running normally, you can continue driving for a short distance, such as driving home or to a repair shop.
However, have your car diagnosed and repaired as soon as possible, as it could lead to reduced performance, decreased fuel efficiency, or even potential engine damage.
If the check engine light flashes, stop driving and follow my guide in the What to Do section.
Why Is My GMC Check Engine Light On?
There are numerous reasons why the check engine light might come on in your GMC vehicle. Some common reasons include:
- Loose or faulty gas cap
- Poor fuel quality
- Catalytic converter issues
- Oxygen sensor malfunction
- Mass airflow sensor malfunction
- Spark plug or ignition problems
Note any recent modifications made to your vehicle have the potential to trigger the check engine light. Even the tire replacement that does not meet the original tire specifications can cause the check engine light and traction control light to come on in your GMC.
Such modifications may result in expensive repairs that fall outside the scope of the vehicle warranty coverage. Furthermore, they could impact the vehicle’s ability to pass an Emissions Inspection test.
Learn more: What the Check Engine Light is Telling You and How to Respond: I explained details about the causes of check engine light in the article.
What to Do When the GMC Check Engine Light Comes on?
If the Check Engine Light Is On Steady
Check the following:
- Fuel cap: Ensure that it is tightly secured to prevent any potential fuel vapor leaks. In case you notice any signs of damage, replace the right type.
- Fuel quality: Using contaminated fuel can impact engine performance and trigger the check engine light. Ensure you’re using high-quality fuel from trustworthy suppliers.
If the Check Engine Light Is Flashing
Step 1: Stop driving
Pull over to a safe location and avoid driving until the issue is resolved.
Step 2: Use a scan tool
Many auto parts stores offer code scanning services, or you can invest in an OBD2 scan tool for your personal use. Connect the scan tool to your vehicle’s OBD-II port and read the trouble codes.
Step 3: Diagnose the problem
Once you have the trouble codes, use our OBD2 Code Lookup to interpret the codes. These codes will provide insights into the specific problem areas that need attention.
Step 4: Address the problem
Depending on the diagnosed issue, you can decide whether it’s something you can address yourself or if you should seek the assistance of a professional mechanic.
Step 5: Reset the check engine light on GMC
Disconnecting the battery can reset the check engine light, but I don’t recommend using this method. Instead, use an OBD2 scanner to connect to your vehicle’s computer and clear the trouble codes. This will turn off the check engine light.
Remember, only reset the light after completing necessary repairs, and if the light reappears, consult a professional.
What’s Next?
The GMC check engine light is a vital warning of underlying problems. By addressing the problem promptly, you ensure your GMC’s ongoing reliability and performance.
Have you encountered any unique situations or found effective ways to address the check engine light? Feel free to share in the comments below.
We’d love to hear from you!
Learn more: GMC Warning Light Symbols and Meaning (FULL list, FREE Download)
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