Why would the service engine soon light be coming on a 2000 Chevy silverado?

Answer 1

There are TONS of reasons - the first , and least expensive, step is to read the codes that the onboard computer is throwing. Instead of spending a lot of money on a code reader, or wasting money by going to the dealership, find an AUTOZONE (or, sometimes MERCHANT's will offer a "we'll check your CHECK ENGINE LIGHT for free) and they'll give you a generic read of the code(s). I say "generic" because the computer DOES throw specific codes; the "we'll do it free" places usually don't have the same kinds of super-readers that the dealerships or high-end repair shops own. But, bear with me for a sec....this may save you some money. If the generic code says, "O2 sensor"....that's not as specific as you'd like (because there are multiple 02 sensors!)...BUT....if ONE sensor is not functioning properly, its a pretty good bet that the other(s) will be failing soon too, since they were all installed at the same time and all were made by the same company, etc. The "generic" code WILL tell you enough info as to which sensor is bad (the one in front of the converter vs the one behind the converter) so....if THAT is the code, then simply replace both behind or both "in front". Follow? Now, where you'll typically get the most common code is for low fuel pressure. If you've never changed your fuel filter...that's a good place to start. The "generic" code will indicate "fuel pressure". If you've never changed the filter....see? BUT, a fuel pressure problem could also be as simple as "loose gas cap"! If your generic code says "fuel pressure", then I'd reset the computer (disconnect the battery for a few minutes and re-connect), and while the battery is disconnected, make sure that the gas cap is tight and the little rubber gasket around the cap is in tact. Keep in mind....a "check engine light" doesn't mean that your computer is throwing codes CONSTANTLY! It means that the computer sensed something at some point while the scan was running and SOMETHING got its attention. "IF" the fuel cap was loose, for example, just re-tightening it will not reset the "check engine light"! You gotta reset the computer (disconnecting the battery is easiest), THEN the light will be off. If the light returns, then the problem was something other than the gas cap. Taking your time and doing a little on-line research can save you a ton of money! A 2000 is relatively easy to work on yourself...at least SOME of the issues...even if you're not a really techie-kinda person. Take the easy and inexpensive shots first.... Hope this helps.