Duramax Lifetime Supporter
Join Date: Oct 2016
Location: Maurice, LA
Possibly a vanes stuck?
Do you have a monitor so you can see your vane position while driving and when Turbo Brake activates? If you do when it first activates vanes should go to 100% and then decrease til the truck downshifts then it goes back to 100% in the lower gear and repeats the process.
2008 Silverado 2500HD CCSB LTZ Diesel
FASS 95 Lift Pump (with Baldwin filters), Edge Insight CTS Monitor on a Windshield Mount, Nicktane Fuel Filter Adapter w/ CAT 306-9199 UHE tertiary fuel filter, Bilstein 5100 Stock Height, Bushwacker Bed Rail Caps, AMP Research Bedstep, Fumoto oil drain valve, Dorman PS Oil cooler, Pioneer AVIC 7200NEX GPS/Stereo, Air Lift LoadLifter 5000 Air Bags.