2019 RS5 Sportback occasionally fails to upshift

[Ravenroy]

I bought an RS5 in June to replace a perfectly good low mileage 2018 S4. The RS5 is basically as fast 0-60 as my last Corvette (2015 Z51). The only problem I have had to date is the occasional failure to upshift, e.g. 6 to 7, 7 to 8 when the tach is showing 1750 rpm or even higher. The failure to upshift cannot be summoned on demand, so the dealership has no clue as to how to fix the very intermittent problem. The only common factor in the sporadic failures to upshift is ambient temperatures > 90 degrees F. It's almost like the engine thinks it can provide better cooling by running faster. Has anyone else had this happen to them ?

[douglasjboehme]

I've only ever had it go longer when I've confused the transmission. When I click the paddles, it always shifts for me.

[-LoneStar-]

I have a S4 but I have had this issue. It does seem to be a temperature thing. Its just odd because I can be in D mode and see the car in 8th at say 50 mph. I can bump the shifter over to manual, not changing drive modes (dynamic, comfort, etc) and it will refuse to shift into 8 when I tap the paddle to upshift. Not sure what the issue is and as you said doesn't do it all the time. If I had to guess, some check of the car (speed, temp, etc) isn't met, so the computer doesn't allow it to shift.