2000 Jimmy. The abs engages easily in light snow while in 2wd. Have no trbl stopping at all in same conditions while in 4wd.
Both hub assemblys were replaced last year which came with new sensors. Also replaced back brakes and rotors. I am about to change front rotor/pads and while im there would like to try and look into the abs issue.
Had the truck 2 years and its done this since 1st snow fall. It occasionally does same thing in wet conditions.
Another thing is i have 2wd blazer rims on my 4wd jimmy.

I could be driving 20mph hit brakes and slide for 30 feet. But in 4wd it stops instantly without the abs noise or pulsing.
could this be an abs trbl even if it works fine while in 4wd? Where should i start?

 

I has simular issues with my 97. the abs would engage at low speeds and the truck would just keep going and going and going till a almost drove through a gas station. what the issue was with mine is someone(cetified shop) put full metallic pads on the front of the truck. The dust would build up against the sensor(magnetic) and the ABS would think the wheels where locked up at low speeds. Needless to say I through out those pads and istaled a set of NON-metllic ones and never had an issue since.
I also had simular symtoms with my Acura and changed pads and all good.
Maybe this help

 

Well I will purchase non metalic pads to install. Thanks for the info. But that doesnt explain why it only does it in 2wd