same thing here when i pull codes, 137 and 138 were blank. as you can see in the last parts of the video. my rear left hub was bad and now after the tt install my rear right has gone out.

 

on my truck the issue is that the front and rear calipers are partially seized. the front left has a caliper guide that is rusted- stuck out.

 

Resurrecting an old thread, I know. Did you ever figure out your codes 137 and 138? While I was playing with my AutoCom tonight, I did a full system scan and found 4 ABS codes. 137 and 138 (twice each). I have not had the Amigos visit since my SLABS failed. The failed unit has been replaced with a SLABS from a 2004 (no more Amigos when restarting with CDL engaged),

I was just really surprised there were any codes, since I have no warning lights.