Okay guys - here was the fix.
There was a service bulletin and recall on my 2017 Suburban that I was unaware of. When I called a local dealership they did not mention the available service bulletin and recall and advised me to bring the truck in to have it diagnosed at a significant cost to me. I believe their suggestion to me should have been to bring the truck in for the recalls and see if that would correct the problem.
I asked my wife about any recalls as the truck is hers and she found this one:
Why is your vehicle being recalled?
If a wheel-speed sensor fails in your vehicle, a software error could cause the vehicle's driveline-protection system to activate when (1) the vehicles electronic transfer case is set to four-wheel drive or automatic mode, and (2) the vehicle is driven between the speeds of 41 and 60 mph. If the driveline-protection system activates, unintended braking on one wheel can occur, causing the vehicle to pull to one side, increasing the risk of a crash. If a wheel - speed sensor has failed in your vehicle, your vehicle's Electronic Stability Control (ESC) and Anti-Lock braking System (ABS) malfunction indicator warning lamps will illuminate and the vehicle's driver information center will display "Service Stabili Trak"message.
Let me be clear here- the only symptoms my truck was showing were the 4 wheel shifter knob being locked in "auto". The "Service 4 wheel drive" in the driver information center, the feeling that the passenger rear wheel brakes were locking up in low speed corning in forward and reverse and a howl in corning at low speeds and a slight wheel hop. Nothing happened at 41 - 60 mph per definition above. No ABS light,. No Electronic stability Control (EBS) warning, No wheel -speed sensor warning, just the "service 4 wheel drive system" and shifter locked in "auto".
This is what the Chevrolet dealer did on the recall.
The dealership will reprogram the electronic brake control module (EBCM). This service will be performed for you at no charge. Because of the service scheduling requirements. It is likely that your dealer will need your vehicle longer than the actual time of approximately 25 minutes.
Until your vehicle has been serviced, you can avoid the risk of unwanted braking activation by driving in two-wheel drive mode.
This instruction would not have worked for me because we could not shift the vehicle into two wheel drive as the shift control would not change settings.
My recommendations to all - look for all service recalls for your vehicle and get familiar with them and check them and have all recalls done first. - May fix your problem.
I am convinced that the first dealer may have double dipped on the warranty recall by charging me and then submitting as recall work.
All good now
I hope this helps.