Unreadable codes

[Leejr57]

I have a 1995 Buick Le Sabre,(basically a bonneville with Buick nameplates), 3.8 ltr. Car was running then just shut down, no spark. Changed the crank sensor, started back up and ran fine. This was a month ago, yesterday same thing happened, plugged in my code scanner with the proper chip. Scanner reads "cannot communicate with vehicle". Has anyone else had this problem and if so what was the cause. I pulled the ecm thinking maybe there was an issue with that but it seems to be fine.

[SSEi95]

I know the 95 Bonneville was a weird year where it had an OBD2 connector, but an OBD1 computer (commonly called OBD1.5). My guess is you are trying to scan it as an OBD2 which won't work. You need an OBD1 scanner with an OBD2 cable. I'm not 100% sure that the buick followed suit, but I assume it would.

[Leejr57]

I'm using a snap-on scanner with the "K-9" chip. Scanner worked fine on my 95 Bonneville just not on the Buick.

[00Beast]

Remove the chip, then let the scanner determine the chip needed. There's a very slight chance that the Buick may call for a different chip. Just give that a shot, and report back.

[Jrs3800]

The Protocall for both the 1995 L36 and the 1995 L27 is the same, but the Programing and the way it functions is different..

By all rights any tool that will read a 95 bonneville should read the 95 Le Sabre..

[Leejr57]

Scanner calls for the "k-9" key chip for that vehicle. As a side note, I pulled the ecm from the Pontiac and plugged it into tbe Buick. Viola!! I can now read the codes. Po325 Knock sensor circoit. I'm thinking the ecm is bad in the Buick.

[Leejr57]

Engine "clunk" seems to come from the trans. end of the engine, toward the firewall. I've unplugged every sensor I can see to see if I could locate the problem. So far no luck. I don't think it is in the engine bottom end. It doesn't do it all the time, just occasionally. But when it does it really is loud. The engine doesn't change rpm or anything.