Seaside Auto Repair

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Why is my check engine light on?

Check Engine Light: A Deep Dive at Wayside Garage

At Wayside Garage in Seaside, CA, we recently had a client come in with a Chevy Volt experiencing a check engine light issue. The modern Chevy Volt, like many vehicles today, is equipped with approximately 30 to 50 different computers, each monitoring various systems and components. 

When diagnosing a check engine light, our first step is phase one testing, where we scan the vehicle's computer for codes. In this particular case, our expert technician, Jonathan, found multiple codes stored in the computer. Some of these codes were even duplicated across different modules.

Decoding the Codes: A Layman's Explanation

To make sense of this, think of the car as the trunk of an oak tree. When we plug the scanner into the vehicle, it's like identifying the trunk. Each code we find directs us to a specific branch, and from there, we may need to examine smaller branches and leaves to find the exact issue. 

Many people think that diagnosing car issues is as simple as plugging in a machine that spits out a magical repair solution. In reality, it's much more complex. Jonathan often works on hybrid and electric vehicles, running tests with tools like fluke meters and lab scopes. It's a bit like playing detective for cars!

The EGR Issue: A Common Problem

In this case, the client was particularly concerned about an EGR (Exhaust Gas Recirculation) issue, a common failure point in many vehicles. Upon inspection, Jonathan found that the problem wasn't the EGR valve itself but rather an electronic issue with the computer. 

Interestingly, this particular issue has led to a recall because it's been reported in thousands of similar vehicles. Unfortunately, due to high demand, the replacement part is on backorder. This means that some of the check engine light codes may persist until the defective component is replaced.

The Interconnected Nature of Modern Vehicles

Modern vehicles are incredibly interconnected. Computers in your car communicate with each other using binary codes. When one system has a problem, it can affect others, sometimes leading to what we call "false codes." This makes diagnosing issues a bit like untangling a web, as problems in one area can cause multiple modules to shut down or throw flags.

Trust Wayside Garage for Accurate Diagnostics

If you have a check engine light issue, it's important to address it promptly to prevent further damage to your vehicle. At Wayside Garage, we use top-of-the-line diagnostic equipment and have a team of certified technicians ready to help. 

Give us a call at 831-899-2425 or visit our website at to schedule your reservation. We'll ensure your vehicle is running smoothly and safely.

Wayside Garage is committed to ensuring effective communication and digital accessibility to all users. We are continually improving the user experience for everyone, and apply the relevant accessibility standards to achieve these goals. We welcome your feedback. Please call Wayside Garage (831) 899-2425 if you have any issues in accessing any area of our website.