so i have code u0029
i cannot control both rear windows or front passenger window.
also cannot operate power mirrors.
i thought it was the door control switch so i bought a new gm one from gmcarparts it is acting exactly the same that i can control the locks and activate the child lock switch but window lock switch will not change just stays off.
on the driver side i tried looking at all the wires they are fine from what i can see but i cannot get the wire harness free from the body side to get the boot further off to see if there are broken wires in there.
odd i can use the key fob to roll all windows down but then i have to run direct power to the motors to get the windows back up from the battery.
also no fuses blown.

 

post your vehicle info please

 

2016 silverado 2500 6.0 crew max lt 150k miles

 

use a multimeter to check for continuity

 

I believe you have broken wires in the door jamb of the drivers door. I had a 2008 and a 2014 Silverado with the same toubles. There were mutiple broken wires in the door jamb. I repaired the wires with solder and heat shrink tubing. Problem solved. If you remove the door panel and the speaker you can pull the harness through the door. Gives you way more room to work.

 

found the wire a bunch the jacket was broken so i tapped those up then taped them together. next year probably buy a new door harness.
the only fully broken wire was red/blue.
this time getting the harness to detach from the door was easy i don’t know why i couldn’t get it before.

 

I do beleive you have found the problem. I taped the cracked ones, and soldered and heat shrink the broken ones. I was told the harnesses are not available. Thats why I repaired the one I had.