the 96 has a primitive problem.
an inspector informed me ,the debug is old school. no obd2 connection for some. I am just one of them..not even implemented to interact with obd2 in any way. I only have spider injection and all the gadgets. I have a May 96 manufacture. Truck untouched, all oem.
5 speed manual oem..It might have something to do with the very lightweight harness. Maybe it was a friday. Who knows?
light on? check speed sensors. these fix in realtime as well.. "reset" is a hoax. You are resetting nothing.
these trucks ring gear lasts as long as the CV..very protected. It has that going for it.
as far as bleeding, these are very passive. not sure where that is coming from.. "air in the abs". I have seen it in comments a few times, and they fade away...probably realizing, you just bleed the lines like every other vehicle.
a most common problem is synching speed sensors. these are way too sensitive. they can't even math a dual brand combo either... need to be identical, same distance into the hole. as these age, iron bulding up on the hubs..odds are astronomical to get it right first try.
The ABS isn't diagnosed through "OBD2", it's diagnosed with it's own wire
in the OBD2 connector. OTOH, if your scan tool won't connect to the engine/trans computer, there's something wrong--either the scan tool has problems, or the vehicle has problems (faulty wiring, faulty computer, etc.) The vehicle by law has to be compatible with OBD2 protocol including connectivity with scan tools.
Resetting the safety switch in the combination valve is a "real" thing. If the safety switch valve has moved out of it's centered position, it has to be re-set "centered" to turn off the BRAKE light on the dash. There is some question about this; my experience has been that the safety switch automatically re-centers; but I've heard enough stories about having to manually re-center safety switches that there must be something to it. I have manually reset exactly two safety switches, both on old Fords. Every GM I've worked on has been self-centering. But I haven't worked on every GM ever, so maybe I've just been lucky.
I've never had a problem "synching" speed sensors. Either they work right, or something is wrong. Sometimes the wire harness is damaged; sometimes the sensor is bad, and sometimes the sensor is contaminated with iron filings from wear in the bearing hub; or debris picked-up from the road in the case of sensors in open-air. Point is, when the harness or the sensor is repaired, replaced, or cleaned as needed...they work as intended. I've never had to play games with sensors to get them to match each other. There was a time I suspected a problem like that on my Trailblazer. Replaced the right-front sensor, which then caused the ABS to act goofy instead of just being totally disabled. At first I thought there was some unusual problem with the new RF sensor. I soon figured out that the
left-front sensor was
also damaged. Replacing that sensor returned the system to normal operation.