What to do about that “check engine” light


The “check engine” light (CEL for short) can mean many different things, from a loose gas cap to a seriously misfiring engine.  It doesn’t mean you have to pull the car over to the side of the road and call a tow truck, however, it does mean you should get the car checked out as soon as possible. If you ignore the warning and wait, you could end up damaging expensive components.

When it begins to flash, the situation becomes critical.

What to look for

Whenever the check engine light comes on, it is important to have a check engine light diagnosis.  A diagnosis involves special computer system scan tools, fuel pressure and electronic testing equipment, specialized technician training, and even licensing in many states. Merely retrieving a code and trying a part, without a check engine light diagnosis, will do little to repair the problem and may even damage expensive emission control system components.  It is rare that a check engine light problem can be fixed simply by resetting it or disconnecting the battery! The light will just come back. This indicator lamp, also sometimes known as the malfucntion indicator lamp, (MIL), informs the operator when there is a problem anywhere in the vehicles electronic engine control system. This system basically includes all sensors, solenoids, valves, actuators etc. that your vehicle needs to operate correctly. After 1996, the auto industry went to a system called OBD II (on board diagnostics).

What we do at E.A.T.

The check engine light is triggered when one or more of the many sensors on the vehicle detects a not-normal reading, There are 2 basic steps we use to determine the cause of the CEL coming on:

1. Read the codes – we look up the fault codes for each vehicle.

2. We research the background for each code, and use factory based diagnostic engine tools, and a vast database of codes. This helps us to determine the true cause and reason for the not-normal reading. It is not often that the sensor itself is bad and requires replacing.

About 7% of the vehicles that have a check engine light indication, are the result of a loose or inadequate gas cap. We will run a check on the vehicle’s powertrain computer (note that some of today’s vehicles have 17 different computers) and will run a series of self-tests. They will only run under certain criteria, and they can be vastly different from manufacturer to manufacturer. Some self-tests are not run until preceding ones have run successfully. So if there is a problem in one particular area that is preventing another self test from running, we may encounter a situation where one problem is fixed, but another still exists. We will work through these until the fault is found and corrected.

If your check engine light comes on give EAT a call or email.