I have a '95 GC Laredo with a check engine light, apparently Auto Zone can't scan it as it's OBDI so I tried the "key trick."

My check engine light didn't flash a single time, just stayed steady on. But my O/D light under the button flashed, how do I find out what that code is?

I got 5 flashes, pause, 5 flashes. ODBI codes say that that means "codes complete", but that's the only one that came up? I tried this about 4-5 times to verify that I had it right.

Please, any help is appreciated as I have to clear the codes out before inspection in October.

 

over drive light is not part of the check engine code key cycle, are you sure you are doing key on, key off, key on, key off, key on?

 

Yeah I'm doing it right, just like you described. I even ran back out and tried again a few times after posting.

I read somewhere that the O/D light can give trans error codes, but haven't seen any way to identify what it means.

 

Tried again and my check engine light flashed the same as the overdrive light.

5 - pause - 5

Any chance its a bad ground or something?
The CEL is always on, but flickeres on and off while driving and at times turns off completely for a bit while on the highway or extended driving.

 

So no suggestions on what to do or what could be the issue?

I'll try again today to ensure I counted right. I'm actually a little more concerend with why the O/D light flashes too, trans issues? It slips a little on the way into second, but only about once-twice a week.

 

I think aamco does free check engin light service at least in Nevada they did.

I had a problem where my obd2 scanner would not communicate with my car and they were able to find the code since there scanner is way better than mine.

 

it is possible that the instrument cluster is what is really wrong, perhaps shorted internally

 

It's a 95 so it's ODBI, at least that's what Autozone said lol. So none of the free places can/will scan it.

Not sure about the cluster, my oil pressure guage is screwy though. Always totally pegged out, I'll see if that's the issue.

 

Technically its not OBD1, but its not OBD2 either. Most people refer to pre OBD2 as OBD1 though but OBD1 is not correct. Anyway as you found out, most places wont give you a free scan on vehicles before OBD2, the systems were totally different before OBD2 and every vehicle manufacturer used different connector and different "language" to communicate with the module(s).

Code 55 means the self diagnostic test sequence is finished, if there were no flash codes before the 55 then that means it passed the tests. I dont know why you are seeing a check engine light but have no codes. I would be curious if a scan tool would show the same thing.

 

Thanks for clearing that up, always feel like a tool when I use the wrong terminology lol.

I saw that that was what code 55 meant, which was why I was confused that I still have a CEL. I'm starting to think it's related to a ground somewhere because it goes on/off depending on how I'm driving.