Reverse light switch?????
Amazon.com: ACDelco 89060011 GM Original Equipment Back-Up Lamp Switch: Automotive
On the 05, there are two back up switches on the trans, and the switches are located on the front of the transmission on the passenger side.
Photo taken looking straight down on the trans, and the right side if the trans is the front side. So look on the right bottom side in the photo and see the two back up sensors with the two black end plugs.
Even at the dealer, should be able to trouble shoot the bad sensor problem with a tech II tool to verify that its the switches that have gone bad, and install the new switches in less than a hour (so don't have a clue where they are coming up with a $400 labor charge).
Also to point out, to check the switches once you have then in hand, just uses a multimeter across the two connectors in the connector socket with the multimeter set to resistance, and push the end button in to see if you get a changer in reading with the end piece lightly pushed in. The reason lightly, the contact is inside the switch, and the contact tabs surface wears.corrode over time ,causing the switch to not work correctly when the trans detent is pushing the end piece in instead.
As for reinstalling the sensors, torque to 15ftlbs and the sensor nut size is 22mm.
After banging my head repeatedly against a 22mm socket (literally, it fell off the transmission onto my face a few times) I realized it's actually a 7/8 not a 22.. hope this saves someone some time and bruising! ;-)




