Scheme 527
Overview
The electrical compass sends the azimuth (direction) information in the 8-directions (N, NE, E, SE, S, SW, W, NW) to the audio-HVAC display unit via the audio unit.
Scheme 528
Starting Operation
When the ignition switch is turned to ACCESSORY (I), the electrical compass unit begins to communicate with the audio unit. Then turn the ignition switch to ON (II), the self-test mode begins automatically.
The self-test function checks for the current voltage, non-volatile memory (NVM), and ROM status in the electrical compass unit. If the unit detects a malfunction while in the self-test, it indicates a malfunction by flashing compass information segments (CAL and NW) in the audio-HVAC display unit.
The electrical compass unit sends the azimuth (direction) information to the audio unit across a UART communication bus. The electrical compass unit receives the VSP signal from the gauge control module via the audio unit. The azimuth information is fixed while parked.
Self-Calibration
The electrical compass unit has a self-calibration function. It detects and compensates for magnetic anomalies caused by bridges, subways and large steel structures. When the vehicle leaves an area with a strong magnetic interference field (2, 400 mG or more), the electrical compass unit automatically begins calibrating. If needed, you can manually calibrate the compass. (see CHECK THE COMPASS CALIBRATION )
See also:
• CONNECTOR TO FUSE/RELAY BOX INDEX