Component Description

Steering Wheel Switch - Message Center 

The message center switch portion of the LH steering wheel switch is comprised of 5 buttons. Each button operates a unique switch within the message center switch portion of the LH steering wheel switch assembly. Each button uses a different resistance value. The SCCM sends out a reference voltage to the LH steering wheel switch on the input circuit and monitors the voltage drop when a message center switch button is pressed. The voltage drop varies depending upon the resistance of the specific button pressed, indicating to the SCCM which switch is pressed.

Low Washer Fluid Level Switch 

The low washer fluid level switch is a reed type switch. The low washer fluid switch is hardwired to the IPC through a single signal wire and is grounded to a body ground through a separate circuit. The IPC provides a reference voltage to the low washer fluid level switch. When the washer fluid level is low, the float drops closing the switch and pulling the reference voltage low. When the washer fluid level is high, the float lifts off the switch and opens the circuit to the IPC sending the reference voltage high.

Compass Module -- Except SYNC® 

The compass module is located in the auto-dimming interior mirror. The compass module operates by monitoring the vehicle position relative to the earth's magnetic north. The magnetic fields generated by the earth's north and south poles are divided into zones that differ from each other with respect to how the magnetic fields appear. Most geographic areas (zones) have a magnetic north compass point that varies slightly from the northerly direction on maps. The compass module utilizes a voltage supply circuit, ground circuit and a communication circuit to provide the compass heading data for display.

Compass Accuracy 

Factors within the vehicle can affect the ability of the compass module to accurately read the magnetic north. Calibrating the compass allows the compass module to compensate for these factors. Driving near power lines, or driving in the area of large iron or steel structures can temporarily change the compass heading. If the compass remains inaccurate after driving near such objects, calibrate the compass. Variations between zones is generally 4 degrees between adjacent zones and becomes noticeable as the vehicle crosses multiple zones. A correct zone setting eliminates the error.