Don't hit the panic button, but don't disregard it, either.
It's a small rectangle hidden among the gauges clustered on the instrument panel behind the steering wheel. It flashes briefly when you turn the ignition on—along with other system checks like anti-lock brakes—to let you know the system is ready to perform its prescribed job.
After briefly flashing at start-up indicating all is well, it is blank and dormant as you drive happily on your way. Then one day, inexplicably, it glows yellow and warns, "Check Engine."
What do you check and why? The engine shows no obvious signs of anything except running down the road in quite contentment.
The Environmental Protection Agency and the California Air Resources Board established regulations requiring on-board diagnostics systems on cars and light-duty trucks (pickups, vans and SUVs) beginning with the 1994 model year. All '96 and newer cars and trucks have a powerful computer which uses second generation on-board diagnostics, or OBDII, technology.
The purpose of the OBDII system is to ensure proper emission-control system operation for the vehicle's lifetime by monitoring emission related components and systems for deterioration and malfunction.
When the OBDII system determines that an emission problem exists, the computer illuminates the dashboard light indicating "Service Engine Soon" or "Check Engine" or displays an engine symbol. This light, usually yellow in color, serves to inform the driver that a problem has been detected and vehicle service is needed.
Warning signs
OBDII assesses engine misfire situations, the most severe of which indicates the possibility that the catalytic converter is in danger of overheating. When this occurs, the yellow "check engine" light will blink on and off.
Don't hit the panic button and stop the car when the yellow message starts flashing. However, it is important to reduce the speed of the vehicle, and take it to a dealership for service as soon as possible. The vehicle should not be driven long distances with the light flashing.
The system is also continuously checking information from the engine and transmission sensors against data stored in its memory. When one of hundreds of faults is found, the check engine light comes on and stays on. This can mean many things, from an oxygen sensor malfunction to a fouled spark plug.
The continuous light tells the driver that something is amiss, and to bring the vehicle in for service. This is not an emergency situation and it isn't necessary to immediately bring the car to the dealership. However, don't drive for more than a few days with the light on.
A not uncommon cause for the light to illuminate is a loose gas cap. Check to make sure it is tightened properly, and if that's the cause, the dashboard light will go out after several trips.
If the problem that caused the light to come on disappears after a few trips— perhaps a fouled spark plug has cleared—the OBDII computer will turn the light off. This is not an indication of a faulty system. In fact, the system is doing its job to verify that a problem existed and was caused by a temporary problem which has gone away. Your car needs no special attention unless the light comes on again.
Remote diagnoses
Telematics—navigation and video entertainment systems, satellite radio and wireless technology—has opened the door for remote vehicle diagnostics. If the "check engine" or other dashboard warning light appears, at the push of a button the motorist can request a diagnostic probe. An adviser can identify trouble codes for the vehicle's major operating systems and is able to detect the severity of the problem. If the vehicle needs immediate attention, roadside assistance can be dispatched. For less severe problems, an appointment with a dealership can be set up.
Telematics, like many new technologies, appeared first on luxury models, but is rapidly moving down to mainstream cars and trucks. Consumer and industry enthusiasts are sure these systems will eventually be as common as AM/FM audio systems.
The glitches that activate the "check engine" light are often nothing a driver can readily detect, but that doesn't mean everything is working properly. There can be a condition that wastes fuel, shortens engine life or could lead to expensive repairs if left unaddressed. And, since the condition is usually emission related, the level of pollutants coming from the tailpipe can soar.
So, if the check engine light comes on, don't hit the panic button, but don't disregard it, either.
It's a small rectangle hidden among the gauges clustered on the instrument panel behind the steering wheel. It flashes briefly when you turn the ignition on—along with other system checks like anti-lock brakes—to let you know the system is ready to perform its prescribed job.
After briefly flashing at start-up indicating all is well, it is blank and dormant as you drive happily on your way. Then one day, inexplicably, it glows yellow and warns, "Check Engine."
What do you check and why? The engine shows no obvious signs of anything except running down the road in quite contentment.
The Environmental Protection Agency and the California Air Resources Board established regulations requiring on-board diagnostics systems on cars and light-duty trucks (pickups, vans and SUVs) beginning with the 1994 model year. All '96 and newer cars and trucks have a powerful computer which uses second generation on-board diagnostics, or OBDII, technology.
The purpose of the OBDII system is to ensure proper emission-control system operation for the vehicle's lifetime by monitoring emission related components and systems for deterioration and malfunction.
When the OBDII system determines that an emission problem exists, the computer illuminates the dashboard light indicating "Service Engine Soon" or "Check Engine" or displays an engine symbol. This light, usually yellow in color, serves to inform the driver that a problem has been detected and vehicle service is needed.
Warning signs
OBDII assesses engine misfire situations, the most severe of which indicates the possibility that the catalytic converter is in danger of overheating. When this occurs, the yellow "check engine" light will blink on and off.
Don't hit the panic button and stop the car when the yellow message starts flashing. However, it is important to reduce the speed of the vehicle, and take it to a dealership for service as soon as possible. The vehicle should not be driven long distances with the light flashing.
The system is also continuously checking information from the engine and transmission sensors against data stored in its memory. When one of hundreds of faults is found, the check engine light comes on and stays on. This can mean many things, from an oxygen sensor malfunction to a fouled spark plug.
The continuous light tells the driver that something is amiss, and to bring the vehicle in for service. This is not an emergency situation and it isn't necessary to immediately bring the car to the dealership. However, don't drive for more than a few days with the light on.
A not uncommon cause for the light to illuminate is a loose gas cap. Check to make sure it is tightened properly, and if that's the cause, the dashboard light will go out after several trips.
If the problem that caused the light to come on disappears after a few trips— perhaps a fouled spark plug has cleared—the OBDII computer will turn the light off. This is not an indication of a faulty system. In fact, the system is doing its job to verify that a problem existed and was caused by a temporary problem which has gone away. Your car needs no special attention unless the light comes on again.
Remote diagnoses
Telematics—navigation and video entertainment systems, satellite radio and wireless technology—has opened the door for remote vehicle diagnostics. If the "check engine" or other dashboard warning light appears, at the push of a button the motorist can request a diagnostic probe. An adviser can identify trouble codes for the vehicle's major operating systems and is able to detect the severity of the problem. If the vehicle needs immediate attention, roadside assistance can be dispatched. For less severe problems, an appointment with a dealership can be set up.
Telematics, like many new technologies, appeared first on luxury models, but is rapidly moving down to mainstream cars and trucks. Consumer and industry enthusiasts are sure these systems will eventually be as common as AM/FM audio systems.
The glitches that activate the "check engine" light are often nothing a driver can readily detect, but that doesn't mean everything is working properly. There can be a condition that wastes fuel, shortens engine life or could lead to expensive repairs if left unaddressed. And, since the condition is usually emission related, the level of pollutants coming from the tailpipe can soar.
So, if the check engine light comes on, don't hit the panic button, but don't disregard it, either.
