Services > Check Engine Light

Your check engine light is a warning sign, but should not always cause panic.

At Waterloo Automotive, we are here to address your every auto repair need, so here are a few suggestions on what to do when your check engine light or “Service Engine Soon” light turns on.

Why did the check engine light turn on?

The check engine light is your car’s response to the computer that monitors the independent systems of your car, so when it turns on, a problem could be occurring in a few different locations. For example, the computer monitors the brakes, steering, engine temperature and other systems by monitoring a variety of sensors which represent the individual states of these systems. If any of these sensors reaches its preset threshold for triggering, the car’s computer will turn on the Check Engine Light to notify the driver.

The best feature about the check engine light is that it usually turns on when even small problems are detected in any of the systems. It is important to pay attention to the light because it also alerts drivers of poor fuel mileage, reduced performance or excessive exhaust emissions, and small problems that can be approached immediately before they turn into big, expensive repairs.

What do I do when the check engine light comes on?

The simplest way to handle this situation is to visit Waterloo Service Center, where we will read the memory to see what fault the computer is reporting. We can identify whether the problem is as simple as a loose gas cap, or can do more extensive testing if required. We have all the equipment and information needed to determine and correct the problem. In the event the problem is something covered under the manufacturer’s warranty, we will notify you, so you can have it repaired at your dealer free of charge.

How soon after the light turns on do I need to bring my car in?

The simplest way to handle this situation is to visit Waterloo Automotive, where we will read the memory to see what fault the computer is reporting. We can identify whether the problem is as simple as a loose gas cap, or can do more extensive testing if required. We have all the equipment and information needed to determine and correct the problem. In the event the problem is something covered under the manufacturer's warranty, we will notify you, so you can have it repaired at your dealer free of charge.

My technician turned the check engine light off and it came back on a week later. Why?

 

The Onboard Diagnostic (OBD) system is consistently performing a variety of “self-tests” to determine if your vehicle is working as efficiently and cleanly as possible. When a potential problem or failure is identified, the system will compensate if possible, and many of these tests are delayed or turned off. This is especially true if you have continued driving with the check engine light on for several days.

Once repairs are completed, the OBD system resumes its self-testing process, and some of these tests require specific conditions to provide thorough and accurate results. For example, one requires an 8 hour delay before starting the engine to provide accurate results while another requires the vehicle to be driven for several minutes above 50 mph. This is why the testing phase is so important to scheduling and conducting a proper repair the first time.

Call Waterloo Automotive or stop by to have your check engine light diagnosed by a mechanic.

Have more questions about your car's lights? Our frequently asked questions help you clear up some common concerns.