My check engine light is on, what should I do, and can I drive my car?
A check engine light is a warning management system. Its purpose is to inform the driver that the vehicle needs some attention. When illuminated, it is typically either an amber or red color. On most vehicles, the light has two stages: steady (indicating a minor fault such as a loose gas cap or failing sensor) and flashing (indicating a severe fault, that could potentially damage the catalytic converter). When the indicator is lit, the engine control unit stores a fault code related to the malfunction, which can be retrieved with a scan tool and used for further diagnosis. Once the fault code is retrieved with the scan tool, it points the diagnostic technician to the area with the problem. The fault code usually has multiple possibilities, and requires additional testing to determine the exact problem. In some cases, (however rare) the fault code will read the exact problem.
So first thing first: Check to make sure your gas cap is on and give it a few more clicks to tighten it up. If that does not take care of the problem, take note to how the car is running.
Check your vehicle for the fowling conditions using this check list.
ü How does the engine sound? If it makes any unusual sound, you should call Shadetree before you drive it.
ü How does the engine start? If it is hard to start or cranks for an extended period, you may want to call Shadetree before you drive it.
ü How does the engine run? Check to see if the engine runs funny. If the engine runs rough at idle, or when on the gas, or has a loss of power. You may want to call Shadetree before you drive it.
ü Is the check engine light flashing? If the light is on and flashing, call Shadetree before driving. This may require your car to be towed to the shop.
ü Is the oil or low oil symbol on? If this warning light is on, you should not drive your car. Call Shadetree before driving.
ü Is there any other warning lights on? Sometimes you can have a low battery light or some other kind of indictor, with your check engine light. If any other light is present you should call Shadetree before driving car.
After you have completed this check list and everything checks ok. It’s most likely you have a minor problem and it is ok to drive your car. You should have your car tested at Shadetree at your earliest convince. Otherwise if you notice any of the symptoms of the above check list, call Shadetree before you drive your car.
Many check engine light repairs are inexpensive to fix. While others are more expensive, it's still important to get them taken care of. Even though the car could be driving just fine, you may be wasting fuel, putting out more pollution and damaging the engine. In Utah you may fail your annual emissions test if the light is on -- especially if the vehicle is a 1996 or newer -- so that's another good incentive to get it checked out.
Whatever you do, don't just slap a piece of black electrical tape over it and go about your business. Cars just need a little love from time to time to stay in good shape, and neglecting a minor issue could lead to bigger problems down the road.
False check engine light triggering is rare, however sometimes your computer system might have had some kind of glitch or just needs to be reset. Also higher amounts of methanol/ethanol (or other additives) than the engine is equipped to handle may trigger the MIL. These burn differently from gasoline and the EFI system may mistakenly interpret the oxygen sensor's readings as being incorrect.
5 Common causes of check engine lights