Overhead Travel Information System

The overhead travel information system (OTIS) gives the driver information that supplements the primary gauge instrumentation. OTIS displays this information on a vacuum fluorescent display (VFD). The OTIS module has four switch inputs. The buttons for these switches are integral to the OTIS housing. There are two buttons on each side of the OTIS. The buttons are labeled US/M, C/T; STEP, and RESET. The driver selects and resets display functions through the use of these four buttons. The OTIS will display these functions:
Compass/Temperature
AVE ECO Average Fuel Economy
ECO Instantaneous Fuel Economy
DTE Distance to Empty
ET Elapsed Time
ODO Trip Odometer

If the vehicle is equipped with the optional Homelink feature, the OTIS will have three buttons located in the center of the OTIS module. The OTIS module receives all of its information over the PCI bus except compass, which is internal to the OTIS module. The OTIS powers up when it recognizes vehicle voltage on the ignition input circuit. OTIS blanks the display, then illuminates all segments of the VFD. It then blanks the display again. During this time, the OTIS sends and receives information over the PCI bus to determine what to display after the two-second initialization. The OTIS displays dashes -- - -) for any of the screens for which it did not receive bus messages during the two- second initialization. These dashes will be replaced by valid information if and when it is received from the bus.