flyinZ

I've got a problem with my 94'z...I have an SES light and both of my fans are on...idles fine(since I replaced the plugs).I tried to scan the car half a dozen times, and it kept saying "no response from pcm.).I sent it back to my tuner, he checked everything out and it was fine. He took my pcm and put it in another car, adjusted the tune for "his" injectors, and the his car fired right up. NO codes, NO fans, nothing!! Our final conclusion is, that it has to be in the wiring of the car. The only recent wiring that was done to the car is when we did an A4-M6 swap. There was some wiring done in the pcm, but Im not sure what.(since I didnt do it.)

Does anybody have any suggestions? Thought about checking out the trans. harness, even unplugging it to see if that helps any..Can anybody help me???

Guest47904

It sounds as though you're trying to use a scanner which is incompatible with your OBDI computer. Without the actual code, we can't help you.

flyinZ

It wasn't a scanner. It was Tunercats, and i was just trying to read it..Kept saying "no response from pcm." Along with the SES light and both fans on..

Shoebox? What wiring would be done, in a A4-m6 swap, since that is what I did a few years ago..Changed the tune, and now...all of this happened. Something wired that shouldn't be or has come apart?

shoebox

Since you say you haven't scanned it, then do so (with a diagnostic scanner-not a tuning program). The SES is on because there is a trouble code and the fans are on because the SES is on. I don't see anything out of the ordinary so far.

flyinZ

Rob, I was thinking the same thing. Luckly, Im in pretty good with a little auto shop, down the road from my folks house. Last I knew he had a Snap-on scan tool.

Thanks guys!

flyinZ

Ok, a little update for ya...

After 2 different laptops, 2 different cables, and a Snap-on scanner, we STILL can't access the pcm..Even just to READ it. The only time we can access it, even with a Tech2, the pcm is in a completely different car.

Any suggestions??

Injuneer

Check the tan data wire from the PCM D30 to the ALDL connector.

Its not likely that any wiring would be done "in the PCM" for an A4->M6 swap. It can all be done externally.

Just for the heck of it, check the fuse for your AIR pump.

flyinZ

Thanks Fred! I'll check it out.

If I remember correctly, there is a wire, that is spliced into..I THINK its a tan one, on the red harness, that plugs into the pcm..

95Blackhawk

Make sure the ground from the socket is correct. This should go down to the ground by the knock sensor.

Injuneer

D30 is on the blue connector.

flyinZ

Well, tonight after work, I went to the garage and started checking things over...Checked the fuses..all fine, checked the ground, both of them...fine. I could not see any of the wires, that run to the diagnostic port..How many pieces, do i have to remove to see them?

I also checked the wiring in the pcm harness's...seem to look alright.

Does it sound like the pcm is locked?

Would it matter, Since the last time it was tuned, he tuned it for Speed Density..Now its running on a MAF tune...

Injuneer

How did you check the tan wire?

flyinZ

I just did a visual inspection..any cuts/bare spots in the wire, corrision,etc. I probably should have put a volt meter on it, correct? What pin should I stick?