Compass: Description and Operation

OVERHEAD TRAVEL INFORMATION SYSTEM (OTIS)/HOMELINK
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.

Setting The Compass
The compass in the OTIS module is self-calibrating and requires no manual adjustment. If calibration is required, the word CAL will be displayed to indicate that the compass is in the fast calibrating mode. "CAL" will turn OFF after the calibration is completed, only if the OTIS/HOMELINK System is not located within a high strength magnetic field.




Setting The Compass Variance
Variance is the difference between north and geographic north. To determine the variance for the area you are in, refer to the zone map below and follow the instructions. The number shown for your area is the variance number for your area
1. With ignition ON, use the C/T button to select the Compass/Temperature display.
2. Press and hold the RESET button for 5 seconds (but less than 10 seconds). OTIS displays the last variance zone and the word VAR. All other display segments are OFF.
3. Use the STEP button to select the proper variance zone number (1-15). Each variance zone represents a 4-degree shift in magnetic variation from central zone 8, which has no variation from true north.
4. After selecting the proper variance zone number, press the RESET switch. The new variance zone is then set and the OTIS will resume normal operation.