I tried to diagnose my car today. I have a 99 SE-L and my check engine light went on three days ago. I have reseted the ECU with a catalyst problem code. Today the light went on again. I tried to diagnose about fifty times but the light refuses to blink. I can't get it to turn off or find out what the code is. Is my ECU bad? Has this happened to anybody else? All help is appreciated. I tried search and couldn't find anything.

 

hm.....cant really help, and dont remember reading anythin about this problem, all i can really say, is to follow the steps real slowly....

 

I tried really slow and I tried many times. I've done it before and it worked.

 

Bump, I still need some help if you guys can help me out!

 

the ECU light doesn't blink or the CEL light doesn't blink ?
do you have an automatic or manual transmission ?

 

Manual and the light doesn't blink. I tried to reset many times and it just doesn't work!

 

If you reset it, then there are no codes to blink. Oh wait, 0505 should blink if everything is ok.. hummmm

Is your CEL light on when the car is running, indicating a problem exists?

Are you sure your actually turning the screw?? Might sound stupid, but it's in a tight spot and could be hard to see and feel. If all else fails you'll have to go to your dealer or a shop near you that can hook up a scan tool and tell you whats wrong.

You can also disconnect the battery overnight. That should reset it.

 

Szymon does your ECU have a screw just like all the previous years or is it one of those weird 99s without a screw?

 

I know I'm turning it because I can see the screw turning. That should also answer your question Neal, yeah I have a screw. I have reseted my ECU before but this time it's not responding. Do you all think I should disconect my battery for a while?

 

I believe AutoZone's (at least the ones over here) will do OBD II code reading for free. Don't quote me on this, but it's worth a try.

 

When the engine is not running and you turn on the ignition without starting the car does the CEL come on?
I have a "99 SE and the CEL does not light. It is not the bulb in my Max. I had my mechanic trouble shoot it after I had checked the bulb myself and my mechanic said my problem is with the ECU. Since my Max is running great I have just continued to drive it because to get a replacement ECU from a salvage yard was $250 without any guarantee.

 

Yeah I believe I need a new ECU. Too bad no one makes a performace ECU for our cars! The only thing is when I turn the key the light is on before the engine is started.