First of all want to say I have been browsing this forum for a few weeks and it has been very helpful in troubleshooting some issues with my truck already and thank you all for having such a wealth of information here.

With that said I still have a few issues I am hoping I can get some help with. 98 Bravada, 4.3 auto, smart-trac, 200k miles.

Got it and the abs, and airbag lights were on, gauges were flakey and had sporadic issues locking into 3rd gear. Found a dead front wheel sensor that got rid of the abs light. Igniton switch was flakey causing the gauge and trans limp mode issues, disassembled it, cleaned/sanded all the contacts, packed it in die-electic grease, reassembled and seems to be working great there.

Found the "service awd" light wasn't lighting during the "key-on" sequence so did some digging found the "atc" fuse was MIA. replaced that and the service awd light would stay off until ~20mph where it would click on.

I pulled the front shaft and the "encoder" motor down. I am a little confused though because mine doesnt seem to have the feedback encoder on it, its just a dc motor with a high gear reduction system. Are the feedback encoders only for the trucks with multiple 4wd modes? Anyway I pulled the system apart, all the way down to checking the brushes in the motor, all seemed fine there. re-greased everything and put it back together. Checked out speed sensors and found one dead sensor so replaced that.

First drive the awd light stayed out so i figured the speed sensor fixed it but i had to temporarily disconnect the tccm to re-mount it properly and get the trim piece back on and now it throws the light on at key-on. I read somewhere that there is a "code 1" that it throws if it loses power; is this something that will flag the light and if so how do i reset it. Otherwise i guess something else is amiss causing the light again.

I have also recently read something about re-setting the airbag system https://blazerforum.com/forum/tech-articles-diy-29/98-sir-airbag-disabling-enabling-procedures-37436/ is this to clear the codes after an airbag has been removed? It is obvious to me the ignition switch has been replaced before and I am curious if disconnecting the airbag would throw a permanant srs code. I have been running around with my ohm meter on the airbag stuff and havent found any dead circuits yet.

I also am having issues with the abs activating itself at low speeds, or when making tight turns in parking lots. I have replaced the drivers front sensor which was bad, and checked the passenger sensor and it ohmed out good. I also peered into the hubs and the ring looked to be in good shape. Anyone know what the air gap is supposed to be so I can check that? Is there a pressure sensor or anything that could be activating the abs even if I am not touching the brake pedal in a sharp low speed turn? The abs appears to work normally under hard braking.

Sorry for the incredibly long thread...

Cliff notes:
Airbag light on, https://blazerforum.com/forum/showthread.php?t=37436 reset it?
Abs activating itself at low speeds
Will code 1 in the tccm flag the service awd light?

 

Single number codes do not apply to the NV136 transfer case such as is in your truck. You must use an enhanced scan tool capable of accessing the TCCM to read the codes. I would recommend that you get those codes read and see what comes up. Check the ABS, SRS, & TCCM codes.

To make sure that the WSS is working properly, you just spin the wheel with your DMM connected. You are looking for a reading of 250mV-AC or greater. Check out --> Brakes - Low Speed (below 5 MPH) ABS Activation