hey guys, trying to diag this issue that just popped up.. I keep getting the ABS, brake warning lamp and the speedo wiggles around.. i cleared the dtc and it keeps coming back.. I also swapped over two of the speed sensors on the transfer case with no luck...

In the spirit of diagnosing, has anyone ever plugged into the rear sensor on the 4l80 for the vss??? I figure if i can do that.. then i can isolate it to the rear section of harness or maybe the reluctor in the transfer case... I came across a post of where the issue was a broken snap ring in the tail shaft of the transfer case... what i find hard to imagine is.... isn't that bearing also snapped ring in place? unless that's the snap ring that popped and the bearing and reluctor are moving around?

just checking if anyone has ran into this.. thanks


SCSB 4l80 swapped Nv246 tranfer case

 

Most likely an internal break in the wiring to the VSS (rearmost sensor). Hold the connectors and tug on the wires a few inches back...the insulation should not stretch. Think mine had a break where the VSS sensor wires from the trans harness plugged into the t-case harness.

 

Check the ground on or near the EBCM also.

EBCM= Electronic Brake Control Module

 

I will check both of those... as an update.. I unplugged the harness at the connector that extends the vss to the tranfer case and plugged it into the rear vss of the 4l80 that wasn't being used and no issues.. so now its either the reluctor inside the transfer case ( since I had already swapped out the actual speed senors) or the section of wiring to it... I will check the ground for the brake module just for ***** and giggles...

I can't tell if the Vss and the rear output speed sensor for the 4x4 module are on the same plane or slightly offset...I know they read the same reluctor wheel in the TCase...