[Phil P]

Hi

Unfortunately the GM product with the OEM brake controller is all tied in to the ABS computer.

The grabbing and realizing was your ABS system preventing you from sliding the wheels.

I am under the impression the 2015 Duramax came with the exhaust brake.

If so use it.

Otherwise don’t allow the speed to build high enough that you need to apply the brakes with a heavy foot. This is done by planning your descent and getting the speed you want before starting down and keeping it there with intermittent brake application.

Our 2009 Duramax doesn’t have the exhaust brake and we have toured the entire western half of the US and did not have any brake problems in the Rockies or elsewhere.

I tow just under the GCW rating for the 3500 Duel wheel truck we have 23,300 lbs the rating is 23,500 lbs.

We test our trailer brakes at the annual axle service by having wife sit in the truck bed and when I tell her she pulls the emergency lanyard and the trailer brakes come on under full 12V from the trailer battery. This will lock up the brakes so don’t do this above 5 MPH. If this process doesn’t lock the trailer wheels then you have a brake problem with the trailer brakes.

We have 235,000 miles on the truck and 125,000 on the trailer both are 2009 vehicles.

Phil P