Cadillac XT5 Steering Assist Is Reduced / P0128 FIX (Thermostat Failure Guide)

So why in the world does a faulty thermostat cause a "Steering Assist is Reduced" message? In my latest video I explain this mystery and everything else you need to know about the thermostat issues plaguing the XT5. Lots on info to help you to get the dealership to fix it right the first time, or even fix it yourself!

Official GM P/N for Thermostat (Water Outlet): 12678779

TSB (Technical Service Bulletin): https://static.nhtsa.gov/odi/tsbs/201...

Same Repair on a GMC:    • 2017 GMC ACADIA DENALI LGX THERMOSTAT...  

0:00 - Intro
1:25 - The Symptoms
5:05 - Why the Steering Assist error?
8:42 - Warranty Coverage?
10:43 - Replacement Part Info
13:00 - Affected years & models
14:02 - DIY Repair Info
15:28 - Failure Data
15:54 - Thermostat Location
18:25 - Outro