bqman

I have a '96 Z28 with a lot of mods (cam, intake/head ported, 3500 rpm Stall, etc). Anyways, to make a long story short, I bought a Bully Dog Watch Monitor and a Jet Dynamic Spectrum Tuner. I plugged both into my PCM port and both got an error that it couldn't read the PCM. I then took my car to Auto Zone and had them plug their diagnostic tuner and it couldn't read the PCM. I checked all the fuses, non are blown. I've had the PCM re-programmed a couple of times to match the mods that I've made. So, now my question is...???? What do I do?

Fuses are good, car runs well (a little rich but well). The only problem is that I can't access my PCM. Is there a way for someone who might have programmed my computer to put a lock on it? Has the PCM port gone bad? Can it not be wired in correctly or a short somewhere in the line? I'm sure if I trouble shoot it, I'll find it, but I'd like to know some possible problems other than the ones I've already mentioned. Thanks.

MikeGyver

It's just a wiring issue. All you need is a ground and the data wire. Look up which wire the data wire is at the PCM and tap into it there and try.

bqman

So I can plug the tuner straight into the PCM? You think the wire has a short? I'm going to look into to it today but you don't think the chip has gone bad? Its brand new and this is the third chip I've put in the car.

MikeGyver

Chip? what chip.

koolaid_kid

You have flash memory on-board the PCM, not the chip in the sense of a 93 model.
Have you tried cleaning the OBD port under the dash? Sometimes those contacts get dirty. If it has been flashed before then the communications have been working, you just need to debug down to the connections. The most obvious is the port itself. Get some electronics cleaner from vatozone and spray them down and wipe them, being careful not to leave anything on the connections.