2014 Denali 6.6 L Duramax Diesel- 2 holes drilled to left of steering wheel

[MDF]

Hey Everyone. I’ve been looking at buying a diesel 6.6 L duramax denali GMC automatic transmission. Both of the 2014 models in separate cities I’ve looked over have  two, 3/8 or 1/2 inch holes drilled on the left side of the steering wheel in the dash. I can tell these are not manufacturer drilled, and was wondering why I have seen this on that model twice. At first I thought to mount the trailer brake controller, but the holes are way bigger than necessary for screw mounting. The holes are big enough they are very noticeable, an ink pen could easily pass through.  So question 1: why drill these two holes?  Both models I’ve looked at have a trailer towing feature engaged by pushing the end of the shifter on the right side of steering wheel inwards. Would that not mean this model also comes equipped with trailer brake controller? I’m concerned the previous owners removed something I will need for trailer towing or some other feature of interest. I can see the gooseneck mount, or trailer hitch and the 7 way round plug, so I’m baffled on why these holes are there in the dash. Thanks  in advance. 

[ember1205]

Having Tow/Haul mode and a factory hitch / wiring does NOT immediately mean that there will be an integrated brake controller. The button on the end of the gear shift is to put the ECM into a different program so that shift points are at higher RPM's and shifting is more "purposeful" to prevent hunting through gears when towing.

[MDF]

Interesting. Thank you.

[2017HD]

On 2014 I think that the 4wd/Lights/Brake controller are all on the dash to the left of the steering wheel - Can't see anyone messing with them. BTW the brake controller is a square hole.

[Josh154]

My guess is a dsp5 switch hole. 

[2017HD]

Could also have been for off road lights that were removed when the rig was sold/traded in.

[MDF]

Thanks everyone!