Wednesday, May 15, 2013
The Ambiguous Service Engine Soon Light
Back in the dark ages, commonly known as the Malaise Era of automotive history, when cars like Ford LTD station wagons and Plymouth Satellites roamed the earth in metallic brown paint, wheezing through emissions choked carburetors and flatulating through primitive catalytic converters, people referred to these lights as idiot lights. At that time, a red glowing light only came on after your car either belched steam, threw a rod and dumped its oil, or caught fire. Cars used vacuum hoses instead of electronics to manage primitive systems and mechanics everywhere were befuddled. Fixing a poorly running engine was more dark art than science.
Today everything is electronic or computerized. People complain about how everything is too complicated for the home mechanic, but I'll bet they never looked under the hood of a 1980 Chevrolet Caprice. Electronic engine management ranks up there with microwave ovens and smart phones in the pantheon of human achievement. It's the reason why cars last longer today and require less maintenance.
I think of the cryptic "Service Engine Soon" light as a reminder, like a post-it note. It's there to remind me to have my mechanic check it out the next time I'm in for an oil change. It probably means one of the many sensors responsible for engine timing, fuel mixture, or exhaust emissions has malfunctioned. Nissans of this era, with the 3.0 and 3.3 VQ series V6 engines are especially prone to these kinds of problems. And I wouldn't be surprised if more than one sensor went bad. Chances are, it will cost me a diagnostic scan and a couple of hundred dollars in parts and labor to make the little orange light go back to sleep.
Posted by Mark Webb