ALDL won't connect - Suggestions?
 

Car in sig, 95 TransAm, with the OBD2 port but OBD1 PCM. I am trying to do some datalogging and tuning on my car with the new heads/intake, and of course want to get it dyno tuned, however I can't connect to the ALDL port. I've tried Scan9495, Datamaster, $EEHack, and Freescan, none of them can connect. Freescan shows the actual feed back from the PCM and it repeats Bad Header when its trying to connect. Yes, I've checked the Cigarette fuse and it is good.

It initially happened one day when I was driving the car. I uploaded a base mail order tune, and did some highway logging. Picked my friend up to go to the 1/8mi track, and it wouldnt log anymore and couldnt get it to connect since. My guess is a wire loose somewhere, but I need a starting point of what wire/wires to look for.

Thanks!

What kind of cable? I always had trouble with the Red Devil River ones. Bought a Moates and it's been great.

I agree with the above having a moates. However even I had trouble with mine at one point trying to data log. I had read somewhere that the cigarette lighter fuse has something to do with the OBD ports, so I replaced it with a new one and it finally connected. Don't know if this will fix your problem but it's worth a try.

I got the cable from http://www.aldlcable.com/products/aldlobd2u.asp . I've had it for about 2 years so it is out of warranty. I also don't want to have to drop $80 on a Moates cable if that is not the issue. Unfortunately no one else I know locally has an LT1, or I would try to borrow a cable from them to test if it is the cable or the port.

Are there any wires or grounds, etc to check first?

Did you order the OBDII cable? IIRC if it's an OBDII cable it will not connect. Not completely sure, but you may have to order a OBDI cable with OBDII data port.

Yes, its the correct OBD1 cable with OBD2 style port. It was working great for a year, then it just stopped working while driving one day. That's why I was wondering if it's possible that a wire or something may have came/broke loose while driving around, etc?

I would bet it's a connection issue within the cable. I'd call aldlcable and see what they say.

In my experience, when it fails to comunicate, pcm is on its way out

I hope this is not the case. I'm going to go ahead and order a new cable, and while waiting for it to come in, I'm going to check around for any loose/broken/damaged wires. If the new cable still doesn't work, then I know its something else going on, and I can return it if its not the issue. I'm just ready to dial in the new heads/intake and track down the rough running at low throttle.

Must have been the cable, got a new cable in, and it connected no problem.