I think I broke my OBDI ECU diagnostics... help!

squirrel · 05-11-2008, 10:32 PM

Okay so I just finished the install of a replacement fuel injector on my 1994 G20. This is an OBDI car. The injector install resolved my misfire problem, and so I had like three codes that needed to be cleared. To check the codes I turned the screw on my ECU clockwise, held for two seconds, then turned it back. My codes are still present (as they should be, until I clear them). So I do the same procedure on the screw to reset the ECU. But instead of the screw reaching a stopping point like it usually does, I feel a *click* and now it turns freely (with no stopping point when turning either direction). Crap!

I started the car and my codes are now off, there is no CEL showing. But I am afraid maybe the ECU is stuck in diagnostics mode or something. So I start messing with the screw again. It still has no stopping point, but I managed to get the CEL to come back on (doh!). Now I can't get the light to go off again. I also can't get it into diagnostics mode. I tried disconnecting the battery for 30 minutes, but the CEL is still on. I am almost certain my car is code-free, and that the light is only on because they are stuck in the ECU memory, but now I have no sure way of knowing.

Did I break my ECU?

Can I get a shop to hook up an OBDI code reader and clear the codes?