PAC NAV-1129 Navigation and Output Module for 11-Bit and 29-Bit GM Vehicles Gm 11 And 29 Bit Lan Data Systems, Designed To Supply 12Volt Accessory, Illumination, Reverse Wire, Parking Break, And Vss. Great For When Adding Accessories To The Factory Data System. Use SWC module with BUS module Plug and play GM navigation & output module for 11-& 29-bit vehicles with an easy 3-wire connection. 12 volt acc output reverse output illumination output parking break input