smg

My 2018 Sierra 2500 came with the DPN (non-power folding tow) mirrors and the dealer swapped them for DL8 (standard non-power folding) mirrors and they only changed the mirrors. The mirror connector was the same. I later went to power folding tow mirrors and all I had to change was the switch, and the mirrors of course. I can't say weather or not the 2500 and 1500 share the same harnesses, but it would seem logical.

There is lots of great information on this thread that has helped me do a DPN to DQS upgrade on my 2018 Sierra SLE with a gas engine. I do not have the mirror and seat memory option (A45) which makes a difference. I thought I’d share my experience in hopes of helping out the next guy. My truck came with the non-power folding towing mirrors (DPN) and I upgraded to the power folding towing mirrors (DQS). Other than the power folding potion, these mirrors are identical. My driver’s door wiring harness 84290984, the body harness, and the passenger harness all had the power folding wires so I did not have to change any wiring. Sorry, I forgot to grab the passenger harness number when I has the door panel off. The only parts I needed were the mirrors (driver – 84691681, and passenger – 84228892) and the power folding switch 23154702 (which has been superseded by 84643953). The passenger mirror is different for gas versus diesel engines as the mirror for diesel has a temperature sensor used for engine braking. As Phil noted at the beginning of this thread, there are two different switches for power folding mirrors. I needed 23154702 (or 84643953) which is required when you do not have the seat/mirror memory because there is discrete wiring from the switch to the mirrors. The other switch (23488411) is used when you have the memory option and the switch communicates with the BCM through serial data bus 8 and the BCM controls the mirrors. Mine did not have wiring for the serial data bus 8. I found the wiring diagram for my truck at https://www.gmupfitter.com/. The switch I needed was on back order, and apparently had been for a while, so I opted to pick one up from the scrap yard and had to find a vehicle with DL3 or DQS (both power folding) that did not have A45 (memory option). I didn’t figure out which vehicles this switch had been used on, but the one I found was from a 2014 Yukon. In order to figure out what harness I had, I opened my door panels before I ordered parts. Once I figured it out and had the parts in hand, the actual conversion was relatively simple. It took me an hour and a half to do the swap (keep in mind I had already taken the panels off once before so it was faster the second time). Phil has posted excellent videos on how to take door panels off and install the mirrors.