Working on a 2005 Chevy Avalanche 5.3 liter. Customer brought it into shop. Customer saying that switch on dash was changing from 4 high to 4 low then neutral and so on. Stated that it was at a Chevy Dealership and they had installed a new transfer mode switch then told Customer that it needed the encoder on transfer case replaced. We installed encoder and vehicle still does not show any light to control shift on transfer case. Checked all grounds on frame and pulled wiring from transfer case to pdc under hood and checked for raw wires and found none, also ohmed all wires and they all tested good. So far a new switch and new encoder and now a new transfer case module has been installed. waiting to program module now but if anyone has any information that might help it would be greatly appreciated.