So I was working on my 2002 4wd blazer and I had it up on jacks to listen for a growl then abs light came on.
I am assuming due to had it in 4wd and the computer saw differances in wheel movements. Anyone concur?
will it go off on its own? Or do i need a code reader to turn off?
Thank you
John

 

could be a hub going bad, Mine was and I changed out the hub and all is good and no ABS light

 

You are correct that different wheel speeds will trip ABS light. It'll go away. Shouldn't be working on anything built after 1/1/96 w/o a scanner. A simple code reader is useless. Get Car Gauge Pro for your phone and a bluetooth ELM 327 transmitter that plugs into the OBD2 port. If you don't have a smart phone download Bluestacks for your laptop.
Or buy a scanner that can at least clear codes and read ABS, trans, and SRS.