Check engine light help!



My 94 Escort runs like a champ and I would very much like to drive it another 164k miles. The problem is that the check engine light comes one immediately at starting…like 5 seconds after turning the engine over. My mechanic spent about 4 hours poking at it and concluded (after installing in a new computer) that the problem is actually in the cicuit box on which the computer is mounted. He doesn’t want to sit for untold hours checking to see which is bad, as he is afraid the cost will exceed the value of the car. Is this somthing I can sit down and do? Any suggestion would be nice, as it truely does run great.


There’s not near enough info provided to make any guess as to what is going on but it sounds like your mechanic has been doing some wild guessing.

So has he tried pulling any codes and what is his reason for replacing the ECM. (computer)


He actually did pull codes, they told him nothing apparently. He didn’t charge me for any of the diagnostic procedure, so I have to assume he is on the up and up. After pulling codes and checking the emission system he put in a different computer to see if that would fix the problem. It did not. He said then that is must be that box it is mounted against. The car actually passes the emissions test, it is only this check engine light that is a problem. The state will buy it from me for 1000 dollars, but the odds of finding another gem like this one are low.


Maybe, the codes told your mechanic nothing; but, they might tell someone here something. Post them and see.


I am going to be gentel (for a change) don’t get annoyed, please, but things are not getting communicated correctly. The first thing that comes to mind is no codes by the numbers. If the light is on, 95% sure there is a number associated with it ( the 5% conceedes that some wiring error may be causing the light to come on, I have not personally experienced this). Then the conclusion that a mounting “box” is the culprit. If it’s just for mounting then how could it be the source of the problem? this is where I say a communication error is happening. “Circuit box where the computer is mounted”. I can’t place this in context.

This can be worked out, if we try.


As it was explained to me the computer has a large number of pins which plug into that mounting box (or that the female receptacle is the computer and the pin in the mount, was a little fuzzy about that). In either case, it is one of those pins which is bad. There is actually a language barrier, this fellows English isn’t stunning and my Mandarin is weak. I also obviously have little idea what is going, hence asking questions on this forum. Be “gentle” or not as you wish.


The codes are STILL needed to ascertain which circuit might have a problem, such as a bent pin in a connector, or whatever. The language barrier seems to be too great to convey useful information to help you get a fix. Bring the codes for further help.


That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.


This is a 94, right? In that case, the codes are OBD-1, not OBD-2 and may not be all that helpful. Seems to me like you have two choices

One option is to spend a lot of time and money figuring out what, if anything, is wrong. My guess is that this is going to be cost effective if and only if you decide that you have always wanted to learn about cars anyway and this is your opportunity. i.e. You work on it yourself (what do you have to lose?). I believe that you can buy a code reader for this vehicle from AutoZone for about $30. You may also want to invest $20 or so in a Chilton or Haynes Manual that will prove to be frequently incorrect, but marginally better than nothing. And you will probably need some tools. Try a thrift store or garage sales.

Or, since it is a 17 year old car and runs fine, simply ignore the check engine light unless/until the car starts running worse. Odds are that it’ll last a few more years and eventually die from an unrelated cause like excessive engine wear or some idiot with an SUV and a cell phone attempting to turn left through the space occupied by your Escort.