Circuit/System Description

The OnStar® button assembly consists of 3 buttons: Call/Answer, OnStar® Call Center, and OnStar® Emergency. The telematics communication interface control module supplies the OnStar® button assembly with 10 V via the keypad voltage reference circuit . Each of the buttons, when pressed, completes the circuit across a resistor allowing a specific voltage to be returned to the telematics communication interface control module over the keypad signal circuit. Depending upon the voltage range returned, the telematics communication interface control module is able to identify which button has been activated.

For this vehicle there are multiple mirror options: with capacitive touch and without capacitive touch. The mirrors with capacitive touch may not have a status LED like other mirrors. In all other mirrors the status LED is green once the vehicle ignition is on and the OnStar® service is active, but for mirrors with capacitive touch the three indicators above the buttons illuminate when the ignition is on. When each button is pressed it's corresponding indicator is illuminated above.