How can I connect my laptop pc to the 1990 Vette to read e.g. the codes that cause the ABS warning to light? And reset?

 

There are a few progams out there that will allow you to read and clear codes.

Is your ABS light on all the time or just as you start to go forward (or reverse)?

 

The light goes on after some hundrede meters and at a speed lika 20-30 mph, and stays on. The ABS function is gone, hard braking causes wheel lock.

 

Don't know about a PC but I checked mine with a GM Tech 1 scanner. Told me what was wrong in a second. It's fixed now.

 

Such a scanner, does is have a part number? Who sells?

 

I think Snap On sells em but lotta$$$$$$$$$$$ ya got a friend at a chevy dealer tell him to hook ya up for a few bucks. If ya take it to a GM dealer they will diagnose it for a fee of course. GOOD LUCK MAN. Pipe

 

The Tech-1 was made by Vertronix for GM delership techs. Originally they were VERY expensive. Now you can get them and the supporting modules used on eBay for a few hundred dollars as the Tech-2 replaced it. I believe that GM moved to the Tech-2 when OBD1 became obsolescent and OBD2 became the standard.

A lot of scan tools will scan the engine/powertrain, but do not have the capability to scan the CCM or ABS. Your 90 has 3 computer modules. ECM, CCM, and ABS. Ease makes a Windows PC based scan tool that will scan all three for codes (DTCs). It will show you more than a Tech-1 and it will allow you to save hours of scans to your hard disk. You can look for intermittants and use the charting features to tune after mods. Send me a PM or email and I'll be glad to send you screen captures of the available parameters for all 3 modules in the 90 Vette as shown in an Ease scan.

 

check the scan and tune section. one of the mods here has some low priced alternatives, Marcho Polo. I think there is info about it in the Scan and Tune tech FAQ.

 

My mail adress is gunnar.hellstrand@afconsult.com. Ease looks interesting. You may also know what kind of connection I need between computer and car and where I can find the connectors?

 

ghd, I'll send you some pics and info by email. For ECM/PCM scanning, bogus is correct, there are several excellent programs that are cheap or even free. You can find a substantial list in the Scan & Tune stickies, along with a TON of great info and resources on tuning. The problem with most of the free and even many of the ones you purchase, is that they scan only the powertrain/engine components. Few of them scan the CCM and the ABS modules.

I'm not putting down the other scan tools, as many of the free or really cheap ones are exellent scan tools at a great price, you just can't beat free. They were made to scan the ECM/PCM and they do a great job. Very few scan the CCM or the ABS, because the author was generally interested in using the tool to do engine tuning, so that is what their tool does. There was no reason to build a tool with a feature they weren't interested in using like CCM or ABS diagnostics.

Your 90 is a GM OBD1 system. The hardware required to scan a GM OBD1 vehicle is basically just a cable with a 12 pin OBD1 ALDL connector on one end and a serial or USB connector on the other. Depending on the scan software used, a propriatary interface may be needed, or in the case of many of the free scan programs, just the cable. You can build your own cable using instructions, schematics, and pictures, supplied from the good guys at WinALDL.
http://winaldl.joby.se/aldlcable.htm

Several of the free scan tools will work fine with a pre-made cable from AKM and other ALDL cable suppliers.
See:
http://www.akmcables.com/
http://www.aldlcable.com/
http://www.customefis.com/cableorder.html