29 typically is a broken brake wire. Repair it then brake releases and code will clear after the truck sees movement for a while. You could have an issue with the speed feedback sensor on top of the brake or the wiring to it or the disc gap may be too large/gets large as the armature rises from worn motor bearing.
Also I have had a vfc card lock 29 on. New vfc was req'd. Only one instance of that.

Sorry Stan yes it does ,

Is the brake releasing? Does it move at all?