Circuit/System Description
WARNING: This page is about a different car, the 2018 Chevrolet Bolt EV. However, it is still accessible from the selected car via links, so may be relevant.
For an overview of the component/system, refer to: OnStar Description and Operation (UE3) OnStar Description and Operation (UE1)
| Circuit | Description |
|---|---|
| Signal | The control module input circuit has an internal resistance connected to 10 V. |
| Low Reference | Grounded through the control module. |
| Component | Description |
|---|---|
| B24 Mobile Telephone Microphone | Each of the speaker output [+] and [-] circuits has a DC bias voltage that is approximately one half of the battery voltage. When using a DMM, each of the circuits will measure approximately 6.5 V DC to ground. The audio being played is produced by a varying AC voltage that is centered around the DC bias voltage. The AC voltage causes the speaker cone to move and produce sound. |
| K73 Telematics Communication Interface Control Module | OnStar provides subscription-based services for communications, security, hands-free calling, navigation, internet access, and remote diagnostics. |