I have the service manual and pages 4-150, 4-156, 4-160 explain the following respectively: Differential lock schematics, Circuit Description, and Electronic Diff Lock Will Not Disengage troubleshooting. I wish I could post this and have it be readable or be able to explain it. (I'm a Pharmacist not an Electrical Engineer)
if anyone else can post this info for ChevyHighPerformance to look at we might have an answer.