What Does a “Check Engine” Light Mean?
Nearly every day here at UpTown, we receive a phone call from a customer who has a “Check Engine” light illuminated. These customers typically fall into several categories: The ones who have been driving around like that for some time (sometimes years), those who have taken the car to an auto parts store to have the codes pulled, and those who call for an appointment the moment they see that light.
Let’s first address the folks who drive around with a “Check Engine” light illuminated for any length of time. A “Check Engine” light is your vehicle’s way of telling you that something has gone wrong and needs to be addressed. You may not even know there is a problem, and you may think that your car is running just fine. That is your car’s computer doing its job: it’s tellling you something is going wrong before it becomes a serious (and potentially expensive) problem. It’s important that you have that “Check Engine” light diagnosed by a qualified professional as soon as possible and have the necessary repairs done.
Then we have the folks who call to tell us they had the codes pulled at an auto parts store. They then reach the conclusion that the code indicates precisely what’s wrong and what part they need to buy to remedy the problem. This, however, is not the case. First, the scanner at an auto parts store can point a person in the general direction of the issue, but these scanners are limited in their ability to provide much beyond an idea of what MIGHT be the problem. Furthermore, the diagnostic tool is just that: a tool. It takes an experienced mechanic to chase down the actual failure and make the necessary repairs.
One common “Check Engine” code is a misfire. The list of potential causes for a misfire includes, but is not limited to, the following items:
- Spark plug
- Spark plug wire
- Ignition coil
- Distributore cap or rotor
- Fuel injector
- Break or short in wiring harness
- Camshaft position sensor
- Crankshaft positioin sensor
- Engine vacuum leak
- Oxygen sensor
- Mass air flow sensor
- Fuel pump
- Engine computer failure
- Valve, valve spring, valve adjustment
- Restricted exhaust
- Catalytic converter failure
- Engine timing
- Mechanical engine damage
So you can see how difficult it would be for the layperson to even begin to figure out what’s going on! Kudos to the folks who call us when they first see a “Check Engine” light. For those of you in the other two categories, save your money and your car by having your “Check Engine” light diagnosed right away by a diagnostic professional.