I have a 2017 Yukon Denali- 53,000 that I recently took in because it at first was bogging down and fluttering going up hills now it seems to do it even on flat roads. It is not throwing any codes. I take it to GM and the report is - inspected transmission fluid found burnt fluid , scanned for codes - no codes, transmission is internally damaged. Advise to replace transmission 6,000.00 . Is this typical for a Yukon and not throwing a code ? I was thinking it was more a fuel issue - but what do I know ? The service advisor asked if I towed with it ( that's what I have the big engine for) . He said that's probably why- which i think is crap. So my question actually is - is it really the transmission ? no codes just some burnt fluid ? I do have the extended warranty that covers it. I have had tahoes for years but went to a Yukon last year .Thanks is advance for any advice.