Bi-directional controls on 2007.5 to 2013 GM trucks

The engineering staff of the unit I have (xTool D8) said GM Silverado's of my generation (2008 & 2011) don't support bi-directional control of the front windows and door locks. It does have control options for the rear and those work.
Anyone notice this with other units?

I have a Mitchell subscription, but not for these trucks (yet) so I can't see the wiring diagram. Would that not suggest the front motors and solenoids are controlled directly by the switches but not the rear? How is it that Onstar can remotely unlock the truck? Different control module?

-Randy

Would you be able to post the RPO sticker for one of the trucks you're working with?

In the case of a 2011 Silverado 1500 LTZ with an LC9 engine that I looked up for giggles, the door lock control DOES change based on RPO codes. AN3 or DL3 has the lock motors controlled by the door lock switches directly. AU3 without AN3 or DL3 has them controlled by relays in the underdash fuse block.

In the same example, rear door lock motors are controlled by the the same two relays in the underdash fuse block regardless of RPO.

Had to run to the shop to take the photos. Both are LTZs. The 2008 is a crew-cab Duramax dually garage queen feather hauler, the 2011 is the wife's extended cab z71. Thank you for your explanation. I thought maybe the D8 might have a software bug, it appears to be working as designed.

Your website (and book) is quite fascinating, I have learned more about these trucks in the last 2 weeks than 10+ years of ownership.

Your website (and book) is quite fascinating, I have learned more about these trucks in the last 2 weeks than 10+ years of ownership.

Ah sorry about that, I'm not Paul. The avatar is a bit misleading... :blush:

Had to run to the shop to take the photos.

Awesome, thank you! I looked up the door lock diagrams on the Duramax and found what I suspected. AN3 has the front door lock motors driven by their respective door lock switches (modules, really). Those same switches/modules are also on the LS-LAN (single wire CAN). Non-AN3/DL3 has all the door lock motors driven by relays in the underdash fuse block. Since the 2011 also shows AN3 on the RPO sticker, you can figure it operates the same way.

If you haven't tried it already, maybe point your xTool D8 at the door modules themselves? :huh: See if the tool can communicate with them directly. You may find the bi-directional tests you're looking for there.