Why is my Check Engine Light on? That is a great question! It’s a question that may have a million answers and that’s only a slight exaggeration.
Modern vehicles have sophisticated engine and body control modules that monitor and control virtually everything that happens in your vehicle. When something is amiss, it may trigger the Check Engine Light. If the issue is serious and warrants immediate service the Check Engine Light will flash.
If certain combinations of fault or error conditions occur the vehicle may go into Limp Mode. This allows the vehicle to be driven a short distance at low speed to ensure you are able to get the vehicle to a safe location, i.e., out of the flow of traffic.
Sometimes all the lights on the dash will light up. Some refer to this as a Christmas Tree. One thing is certain: When it looks like all the lights are on, your vehicle needs to visit a quality automobile repair shop as soon as possible.
Answering why the check engine light is on is, fortunately, relatively easy. On Board Diagnostics store fault codes which can be accessed by our scanners. But there is a catch.
Knowing what went wrong with a specific system or component is rarely enough information to effect a complete repair. This is where the skills of a qualified mechanic come into play. It’s not enough to know what happened. We need to know why it happened.
If we don’t fix the underlying problem, then replacing a failed component may quickly lead to failure of the newly replaced component.
One piece of good news: sometimes the check engine light comes on for a simple reason like a loose gas cap. This is when a complimentary “pulling of the codes” is most helpful.
More serious issues warrant a visit to a qualified repair facility to allow a thorough diagnostic inspection and repair.