There are hundreds of possible issues that can trigger the Buick check engine light to come on. To find out why your Buick to check engine light is on, read the fault codes with an OBD-II scanner.
MAF Sensor - Mass airflow (MAF) sensors can become clogged with dirt over time, especially if performance filters are used. A dirty MAF sensor will give false readings, resulting in incorrect air-fuel mixture and engine running issues. In most cases, dirt buildups can be easily cleaned off with a MAF cleaner fluid. Another possibility is a loose connector. Related Code: P0102
Various vacuum leaks can cause engine running issues, especially noticeable at idle or low engine speeds. Tracking down leaks can sometimes be difficult, and you may need to use a smoke generating machine. Related Code: P0171 - system too lean
Catalytic Converter- Any higher-mileage Buick will likely have some emission control issues triggering a check engine light. In most cases, it is either caused by a clogged catalytic converter or a faulty downstream O2 sensor. Related Codes: P0410 and P0420
Variable Valve Timing Issue - Problems with Variable Valve Timings are quite common on a 3.6L V6 engine. Furthermore, to check the engine light, you will notice a lack of acceleration, stalling, and poor throttle response. The problem is usually within the timing chain, which needs to be replaced as soon as possible. Related Code: P0008
EGR Valve - the EGR-related problem is, in most cases, caused by a carbon buildup within an EGR valve. While this will not generally affect engine performance, you might have a bit higher fuel consumption. If not too extreme, carbon buildup can be cleaned with EGR cleaner spray. Related Code: P0401
Engine Coolant Temperature Sensor - A bad coolant temperature sensor is a fairly common fault with some Buicks. This will result in false temperature readings on your dashboard, causing rich engine operating conditions. In addition to the sensor itself, make sure the wiring is not damaged. Related Code: P0115
Oxygen sensor- O2 sensors may fail, triggering the check engine light to stay on and fuel efficiency to decrease. O2 sensors monitor oxygen levels in the exhaust, which helps the engine control unit determine the fuel mixture. An engine control unit can determine whether the fuel mixture is rich (less oxygen) or lean (more oxygen).
How to Reset Buick Check Engine Light
The following steps will help you learn how to diagnose and reset the Buick check engine light.
For this procedure, you will need an OBD-II scanner. If you don't have a scanner, you can purchase one online or stop by at your local auto parts store to have the codes read free of charge.
Park the Buick and turn off the ignition. Set the parking brakes.
Locate the OBD-II port under the dashboard and plugin your OBD-II scanner.
Turn on the ignition but do not start the engine.
Allow the scanner to turn on and communicate with the vehicle.
Read the codes by pressing Read Codes or Read Fault Codes on your OBD-II scanner, depending on the scanner. Reach each code to learn more about possible codes. To clear the check engine light, you need to fix the underlying problem before resetting the check engine light.
Fix all issues found in step five. Come back to the main menu and select Clear Fault Codes, then OK.
The instructions worked in 1996, and newer vehicles such as Buick Enclave, Lesabre, Lacrosse, Verano, Regal, Lucerne, Rendezvous, Park Avenue, Allure, and Encore.
What does it mean when Buick Check Engine Light Flashing On and Off?
One problem that must never be ignored is a check engine light flashing, especially if accompanied by engine shaking and juddering.
A check engine light going on and off intermittently signals an engine misfire, causing damage to the catalytic converter and other engine components.
It is not recommended to drive the vehicle if the check engine light is flashing.
Common problems that can cause the Buick check engine light to flash on and off include old spark plugs, bad ignition coil, bad mass airflow sensor, or a clogged catalytic converter.
Buick check engine light or service engine soon light may come on for many reasons.
The first step is to check and tighten the gas cap. The check engine light may require a couple of days to reset on its own. An OBD-II scanner can be used if you want to reset it as soon as you tighten the gas cap.
If the gas cap is not loose or damaged, the next step is to read the fault codes using an OBD-II scanner.
You can take your car to a workshop for a complete diagnosis or get your own scan tool. These devices come in all shapes, sizes, and prices to choose from.