d16tuner

OK, I think I fried my ECU. I was testing the o2 meter I built, and I think the bottom of the breadboard accidentally shorted against the radiator cap while I was testing the signals with my multimeter. I had it temporarily connected to the ground, power, and signal wires between the o2sensor and the harness connector. I was getting 14+/- v at the positive and a fluctuating voltage (0-1v) at the signal like I was expecting. Then - CRAP!

Here are my symptoms:
Now I'm getting .49v at the power and a low signal voltage, and if I up the rpms the positive voltage rises to 2-3 volts and stays around there.

It backfires and pops (rich) when I let off the throttle, and it gets close to dying when the revs drop all the way, then it catches.

The indicator lights that are on in the cluster kind of waver in brightness - wierd looking.

My cel comes on after the car runs about 10 seconds and I'm getting codes 41, 65, and 20 primary and secondary o2 heaters and electrical load detector.

Clearing the ecu didn't help.

Looks like it has given up on reading the o2 and is just dumping fuel. I'm guessing I blew the heater circuit in the ecu? Is it dead, or what do you suggest trying? Think it is possible to resurrect it (new chip on the ecu even)? HELP!!!!

d16tuner

OK, got more info to add. Someone else mentioned that his is doing the same exact thing and replacing the ecu had no effect, so I'm close to crossing that off. Good cause I don't have to replace the ecu. Bad cause I have no idea what the problem is! All of the lights in the car (headlights, dome, dash, etc) pulse at night. It is crazy looking. I haven't driven it yet, but in neutral if I try to hold the revs at a certain point they will drop and then come back up and then drop and keep repeating - it won't hold steady. Anyone have an idea what I could have done

bobski

check all the wiring for and the O2 heater elements themselves (i take it that's where you were drawing your power?). you'll need a wiring diagram obviously, but it seems likely to me that the two O2 sensors share a power source and you blew a fuse or killed the wiring that feeds it, so start there.
if it's a wiring problem after all, that alone might cure the ELD CEL code. if the wiring checks out, try a different ECU and/or ELD.

d16tuner

I went out awhile ago and pulled all the fuses and the backup fuse was blown. Shoulda done this at the get-go, but in my panic I wasn't thinking. I'm getting to be too dependant on forums! Anyway, when I remembered, I went out and had a look-see, and whaddya know? Hopefully that is the problem. I'll find out tomorrow when I replace it for sure.

d16tuner

Backup fuse wasn't it. I checked this morning under the dash and everything was fine but the ALT speed sensor fuse. BINGO. K.I.S.S - keep it simple stupid. All was well after that but a code 13, which I cleared the ECU for. Yay. I'm good to go! Thanks for adding me to your prayer lists everyone!

Seriously. Don't add me to a prayer list. EVER. It'd creep me out.