The check engine light came on in one of our cars sometime last week. Now before someone starts saying “I told you so that’s what you get for driving a POS”, it’s not on my Ford Escort – that one burned out a long time ago 😛 The light came on in my wife’s 1999 Honda Accord which well it’s worth at least 7 Escorts so I actually go to worry about the car getting wrecked which means I’m going to have to do something about the light.
Now usually the light comes on for something trivial such as an emissions problem or I’ve heard of it even coming on because your gas cap isn’t on tight enough. The beauty of the check engine light though is that you have absolutely no idea what the heck the problem is. It could be the gas cap or it could mean that within the next 5 miles your engine will seize up and your car will be rendered useless (although for serious problems I’ve heard it actually flashes). In order to really find out what the check engine light means you need to take it to a mechanic who can hook up some fancy electronic due-hickey to your car and tell you what the code is or purchase one of these gadgets yourself. It sounds like generally there is a fee (especially if you go to a dealership – note: don’t go to dealerships) just to find out what the code is, although I heard that all AutoZone stores will do this for free (can’t find confirmation on their website)
Now the ingenious thing would be to replace the check engine light with a small LCD that would give you the error code and which you could simply give to the mechanic over the phone or <gasp> be able to look it up in the owner’s manual or online. Of course then the dealerships couldn’t make a boatload of money telling people that they need to tighten their gas caps 😉 Another reason check engine lights can come on is just routine maintenance. If the manufacturer thinks you need maintenance every 25k or 50k miles they will just have the check engine light come on. You can reset this by disconnecting the battery, pulling a fuse, or doing some hokey pokey with pushing 5 buttons while turning your key to the 2 slot, your radio tuned to 89.3 and your foot on the clutch (YMMV and some people do not recommend this because it completely clears the computers memory and it needs to relearn everything so your car won’t run at top performance right away). If you are able to reset the check engine light by any of the previous methods and it stays off it means it was just a routine maintenance thing, if it comes back on then you’ve got a problem that needs to be addressed.
Seeing as how this hopefully won’t happen that often I won’t be purchasing my own scanner (even thought the geek in my wants to) and seeing as how AutoZone hopefully will read the code off for free I will be taking the vehicle to them. Then I can decide whether it’s something serious that needs to be fixed or if it just needs a little tape over the light 😉