When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hey there bit of a issue with a 6l80 that at random moments feels like it is dropping into neutral while driving along, it will do it four or five times in a 10-15 second period and come good and may not occur again for a few weeks. Scanning with HP Tuners just shows trans slip and nothing else.
So far I have
Pulled the pan, all looks clean, changed to large pan and correct filter with new trans fluid.
Pulled apart valve body, 8 check ball style all perfect no wear in check ***** or separator plate.
Tested resistance across all the solenoids on the TECHM and all are in spec
Car is a 2015 VF SSV L77 6.0L Commodore Trans slip PCS 1 Cmd pressure rising
When it occurs and what gear is odd too, the most times it happens is when first selecting drive it will feel like it is bucking and if given any accelerator will buck violently. If i put the trans into sport mode and while still stationary use the paddle shift it reduces bucking in second and stops in third. The only other times it really happens is when cruising at light throttle around 110kph in 6th on the freeway. The pic in my first post was while i was using cruise control on the freeway an hour into a trip, revs go mental for a few seconds then returns to normal and drove another hour or so without issue.
have you tried turning the slip learn back on? there are some funny faults i see in the 6 speeds related to the learn/tq management that never seem to clear.
also what year/model is this transmission? the first couple years were kinda hinky
The tune is very important here!
I would be very careful not to mess around on your own... and have the unit programmed by someone familiar with the transmission and HP-Tuners.
Some more of the guys who use HP-Tuners, hopefully will chime in (as Doug did) and offer more help.