Troubleshooting, Warranty & Recalls

911 topics in this forum

1. Side detection temporarily unavailable

   By Irish80, October 8, 2019
   • 2 replies
   • 22.7k views
   • 
   • Dhamilton07
   • September 17, 2024

2. Brake Controller:

   By Tucson Jack, December 13, 2021
   • 9 replies
   • 22.6k views
   • 
   • redwngr
   • January 2, 2022

3. Traction Control Activating on Left Turns 1 2

   By Tville, November 3, 2019   

   • 2020hd
   • 2020 l5p
   • (and 1 more)

     Tagged with:

     • 2020hd
     • 2020 l5p
     • DenaliHD
   • 23 replies
   • 22.5k views
   • 
   • Hagar68
   • September 15, 2023

4. Leaking rear window 1 2 3 4

   By redpat2061, September 24, 2020
   • 50 replies
   • 22.5k views
   • 
   • Guy Fox
   • February 26, 2025

5. Any alignment pro's? I want more Caster!

   By FirstAscent, August 6, 2020
   • 9 replies
   • 22.2k views
   • 
   • FirstAscent
   • August 20, 2020

6. Tire Pressures

   By ManyCamaroz, December 1, 2023
   • 10 replies
   • 22k views
   • 
   • Wxman
   • December 2, 2023

7. 2020 Chevy gas harsh downshift 1 2

   By Nathan Leslie, February 24, 2020
   • 18 replies
   • 21.8k views
   • 
   • GMCustomerService
   • November 28, 2022

8. 6L90E (gas truck) 2-1 downshift CLUNK 1 2 3

   By Epsilon Plus, September 3, 2022
   • 35 replies
   • 21.2k views
   • 
   • AmericanPie
   • August 17, 2025

9. 2021 GMC Sierra 2500 Denali HD Tow Mirror - Issues 1 2

   By 2021GMCLP5, September 22, 2022
   • 29 replies
   • 20.8k views
   • 
   • Fgates1
   • January 25, 2025

10. Onstar fuse location?

    By Tomski12, June 9, 2024
    • 6 replies
    • 20.6k views
    • 
    • Kawn
    • March 1, 2025

11. 2500hd duramax towing mpg

    By MikeZ65, June 3, 2022
    • 9 replies
    • 20.4k views
    • 
    • KC Desert
    • June 20, 2022

12. 2021 Duramax issues, less than a week old.

    By Joe_Lee, December 26, 2020
    • 10 replies
    • 20.1k views
    • 
    • K3500WT
    • August 16, 2021

13. Ticking noise on new truck

    By dquest, November 3, 2021
    • 11 replies
    • 19.8k views
    • 
    • Makiman
    • February 3

14. Side camera calibration to align with front and back

    By Jim-GA, July 27, 2023
    • 9 replies
    • 19.8k views
    • 
    • BainMan
    • February 9

15. 2021 2500hd trans problem?

    By Daler442, March 13, 2022   

    • 2500HD
    • 2021silverado
    • (and 1 more)

      Tagged with:

      • 2500HD
      • 2021silverado
      • tranmission
    • 10 replies
    • 19.5k views
    • 
    • MRanderson
    • April 1, 2024

16. Transparent trailer won't calibrate 1 2 3

    By Topath, June 27, 2023
    • 41 replies
    • 19.2k views
    • 
    • Dustin Marshall
    • July 20, 2025

17. low engine temperature? 1 2

    By bass mechanic, October 11, 2019
    • 21 replies
    • 19.2k views
    • 
    • CNY_AT4
    • December 1, 2019

18. Loose Steering

    By jamco44, October 16, 2020
    • 10 replies
    • 19.2k views
    • 
    • Michael621
    • June 21, 2022

19. Service keyless start system comes up when I start my vehicle

    By don penney, September 23, 2021
    • 6 replies
    • 19.1k views
    • 
    • Darylk
    • February 10, 2025

20. AC Drain

    By RickSt, July 4, 2023
    • 5 replies
    • 18.9k views
    • 
    • Paul Wall
    • June 1, 2025

21. TOWING MIRROR 2021 GMC 2500HD

    By coopermj, December 1, 2020   

    • towing mirror
    • hd surround
    • (and 1 more)

      Tagged with:

      • towing mirror
      • hd surround
      • repair
    • 7 replies
    • 18.8k views
    • 
    • rod120
    • January 19, 2021

22. Abnormally rough ride 1 2 3

    By reb0957, October 15, 2023
    • 37 replies
    • 18.7k views
    • 
    • asilverblazer
    • December 4, 2023

23. High Beam Flash with Left Turn Signal Engagement 2020 2500HD High Country

    By Benthecuban, September 15, 2021
    • 13 replies
    • 18.7k views
    • 
    • Denali1986
    • January 17

24. 2020 GMC 2500 HD DENALI TRANSMISSION PROBLEMS

    By tkcrane89, December 4, 2019
    • 5 replies
    • 18.6k views
    • 
    • JBRLLC
    • November 22, 2020

25. Upper Steering Shaft replacement - 2020 HD

    By jeez, February 6, 2021
    • 12 replies
    • 18.4k views
    • 
    • 2024Denali
    • May 17, 2025