Ok, my "Check Engine" came on the other night. It comes on a few minutes after driving. I pulled the Koer/Koeo codes, and the same one appear that have been there for the past who knows how long...Hego sensor, fuel pump secondary, and code 11.

Now my oil pressure, water temp gauges read just fine (mechanical gauges). The battery light has been on/off which I think is my alternator.

So...what causes the "Check Engine" light to come on?

 

first thing you should do is disconnect negative battery terminal for a few hours or overnight then run her for a day then get the codes..

to reset the computer....and get new codes....

also get codes while engine is running, and while engine isnt running..


and of course not all problems have a code, and the codes just lead you to the problems not give you the awnser......



also is it running well...what is the problem besides engine light.....

also what year and engine do u have

 

info is in my signature...351W 89 bronco

No problem other than the light being on...

I already ran both sets of codes KOER(Running) KOEO(Off). Still the same codes as previous...about a month ago.

??

I guess I'll kill the battery connection (and all my presets! ) But It won't fix the problem...just hide it for a short time.

 

no, it won't fix the problem, but it will reset the codes. If you haven't fixed the problems from the other codes, then no point in reseting the comp (and your presets). First of all, have you found out what the "code 11" means? Keep in mind that any of the intermittent problems your engine might have (such as the sensor or fuel pump problems) will trip the light each time they register in the computer, even if the code already existed.

Let's say (strictly hypothetical here) you had and O2 sensor go out and it tripped the light and a new code. If you replaced the sensor, fixing the problem, but did not clear the codes... the code stays, even though the light goes off after a few miles. Then let's say that the new O2 sensor goes bad. Your light comes back on, but no new codes are entered since it was already there.

Same concept for an intermittently failing sensor. it fixes itself, so the light goes off but the code stays. Then the next time it fails, the light is tripped but no new codes. Of course this may not be your situation, but it is something to think about. Have you ever replaced the bad sensor? If so, it's a good idea to reset the comp then let it trip again with a fresh set of codes. If not.... start with that sensor

-Josh