ROLNSLO

Maybe? Most of us that did this have the IO4/5/6 MyLink systems but someone mentioned in this thread, http://www.gm-trucks.com/forums/topic/169324-reverse-camera-update/page-1, that even the base WT trim with IO3 had the camera as an option so it may work on your Sierra. I'd confirm with your dealer before spending any money on parts.

Yes, you can add the OE rear camera to a truck that didn't have that option from the factory. GM was kind enough to at least put the wiring in place whether the truck was ordered with it or not. However, it can be a pain to get the MyLink (HMI module) software updated to accept that there was a camera added later. The pain isn't on GM's side, it's likely going to be your dealer's service department not understanding what to do. I just went through this last month. Parts you'll need: 1. New tailgate handle with opening for camera (I bought a new take off from ebay for $24) 2. GM camera (Found a GM dealer online that sold them for $105, not the list price) 3. 2 screws that attach the camera to the tailgate handle (had to order @ $4 each) The service department will need to open a case with TCSC (GM Techline) and have them update the VIN in their system to add the rear vision option to the truck's vehicle record. There is likely going to be a charge to the dealer to do that ($50). Once the VIN is updated, the service tech can then update the HMI module software via the standard software update process. After the HMI module is updated, the truck should display a black screen with the guidelines on the dash display screen when you put it in reverse. Plug in the camera into the RC port on the junction box behind the rear bumper and then MyLink will display the camera image instead of a black screen. Total tech time should be less than an hour. PM me if you need more details or part numbers. Your best bet is to get your dealer to put it in writing that 'they' will add the rear view camera as part of the sale so they are stuck paying for parts and time to get the MyLink system updated instead of you. Doing it myself, even buying parts as cheap as possible, it still cost me about $300 for parts/labor, with the majority going to the tech's time he spent with GM's Techline support team trying to figure out what to do.

http://www.gmupfitter.com/files/media/photo/578/Sierra_Silverado_Electrical_Body_Builders_Manual_Service_Manual_2015_en_US.pdf Have fun, it's 898 pages but likely has what you need. I'd recommend downloading the PDF file so you have a copy if they remove the link from http://www.gmupfitter.com/.