Many vehicle owners are perplexed by the 'Check Engine' or 'Service Engine Soon' light on their automobiles. Cars, trucks, and vans have these lights-one or the other (though some vehicles may have both lights). These lights can be confusing to a great number of people because they are so vague. Seeing either of these lights come on is much different than seeing the
oil light come on. When the oil light comes on, a vehicle owner knows that there is an issue with the oil-it is very straightforward and easy to understand. However, with the 'Check Engine Light' or 'Service Engine Soon Light', the answer is not so clear.

The first area of confusion stems from the fact that some vehicles have both a 'Check Engine' and a 'Service Engine Soon' light, whereas other automobiles have only one or the other. In vehicles with both lights, each serves a different purpose. The 'Check Engine' light works to warn drivers of possible problems in the engine's fuel system, exhaust system, or emissions system. The 'Service Engine Soon' light is mean to warn people that maintenance needs to be taken care of with the vehicle (including changing bulbs or fuses, for example). In automobiles that only have one or the other of these two lights, the light can serve to warn drivers of any of these possible issues.

Newer models of vehicles have engine lights that can present in two different colors-yellow or red. When a 'Check Engine' or 'Service Engine Soon' light illuminates in yellow, drivers are to understand that they should have their automobile checked at their convenience. In other words, their vehicle may be having an issue; however, it is not a high priority concern. If, though, one of these lights happens to light up as red, drivers should pull over and turn off their vehicles immediately. Drivers who fail to do so may do further damage to their vehicles.

When automobile owners take their vehicles to a mechanic to have an engine light issue checked out, there are many possible diagnoses that the mechanic could end up finding. Most mechanics will use a computerized diagnostic code scanner to try to figure out what the problem could be. These scanners can help to show issues that the onboard vehicle computers may be having.

'Check Engine' and 'Service Engine Soon' lights come on when an automobile's computer finds an error during a routine check of its systems. Each time a driver starts up his vehicle, the onboard computer runs through a routine series of system checks. This routine covers all of the sensors and components on the vehicle. So, one of these lights can come on while a person is driving-at any point during the drive-as the computer runs through the series of checks. As soon as the computer comes across an error, the light will come on. Sometimes, the lights will come on only if the vehicle is at a certain temperature or speed, also.

These 'Check Engine' and 'Service Engine Soon' lights can be tricky to understand and diagnose-this is definitely an issue best left to an experienced mechanic.