If the ABS computer will not communicate with the scanner, what should I look for? I can perform full diagnostics on the ECM, so I know the ALDL is not completely dead. The ABS computer terminals are clean and secure. How can I test continuity in the circuit to the ALDL? Can I trigger the ABS computer codes by jumping terminals on the ALDL to verify that the problem is with the scanner? My vehicle is a '93.

 

Yes, you can put a paperclip between the two and it will flash the codes through the service engine light. Jump the top two right terminals.

http://shbox.com/1/dlc2.jpg

 

It could be different on 93's but you can't get abs codes with any of the scanners sold for do it yourself use. The only way I could get my abs codes was to go to the dealer. If you have already tried a scanner I doubt shorting the pins and flashing the codes will give any more information.

 

You will need a GM tech II scanner to retrieve the ABS codes.

DEALER

 

I'm using a Snap-On scanner, which should be able to pull ABS codes. I will see if I can borrow a Tech II. Can't say I'll be too pleased if it is the scanner in this case.

 

When I couldn't get the abs codes with a Tech II it turned out that the abs computer was the problem. I'm sure you know but the abs uses a seperate computer under the dash on the far left side.