I am sorry for the long wait
this is a common issue for these transmission
i am sorry to say a transmission shop or the dealer will have to perform this bulletin repair to your transmission or replace it depending on how it looks inside
you can always get me back through this post for any follow up anytime
there is even a bulletin on this issue
Bulletin No.: 09-07-30-012F
Date: September 26, 2012
Subject: No Reverse, 3rd or 5th, Check Engine Light Illuminated, DTC P0776 (Replace 3-5 Reverse Clutch Plate (Waved)
2008-2009 Buick Enclave
2008-2009 Chevrolet Equinox, Malibu
2009 Chevrolet Traverse
2007-2009 GMC Acadia
2007-2009 Pontiac G6
2008-2009 Pontiac Torrent
2007-2009 Saturn AURA, OUTLOOK
2008-2009 Saturn VUE
All Equipped with 6T70/75 6-Speed Automatic Transmission (RPOs MH2, MH4, MH6 or MY9)
This bulletin is being revised to update the Warranty Information. Please discard Corporate Bulletin Number 09-07-30-012E (Section 07 - Transmission/Transaxle.
Some customers may comment about an SES light and/or no reverse and may also comment on a slip/flare or harsh shifts in drive range 3rd and/or 5th gear. Upon investigation, the technician may find DTC P0776 (Clutch Pressure Control (PC) Solenoid 2 - Stuck Off) set. Any one of the following codes may set independent of each other as a result of this wave plate breaking: P0777, P2723, P0717, P0716, P2715, P2714.
This condition may be caused by a broken 35R clutch wave plate allowing the apply piston to over-stroke the piston to leak and causing loss of apply. This normally will not occur before approximately 32,000 km (20,000 mi). Debris generated by the condition can affect the operation of the speed sensors and other clutches.