What is the CAN bus in my car? And how does Pearl RearVision use it?

The RearVision Car Adapter connects to your car’s OBD, or On-Board Diagnostics port. This interface provides power to the Car Adapter and also allows it to communicate with your car using a system called the CAN bus, or Controller Area Network bus. CAN is a standard design that allows different parts of your car to communicate with each other.

RearVision uses data coming from your car’s CAN bus to trigger aspects of the Pearl App experience. For instance, using data passed from the CAN bus to the Car Adapter, the Pearl App can detect when your car reaches 10 MPH, which triggers the Pearl App to display the App Launcher. (See our related articles for more details on the App Launcher.)

Unfortunately, some model years of cars, ranging from 1996 - 2008, do not utilize the CAN bus --  and never will. RearVision still works just fine on these cars, as the Car Adapter can still be powered by the OBD port. However, because it can’t “talk” to your car, there are some elements of the experience that will differ slightly:

  • As mentioned above, RearVision uses the CAN bus to detect when your car surpasses 10 MPH. This triggers the Pearl App to display the App Launcher. But when using the Pearl App in a car that doesn’t utilize CAN data, you will need to double tap the screen to manually end the video after you’re done backing up, or wait for the default 60 second delay to end, at which point the App Launcher will appear as expected.
    • Alternately, you can manually set the delay time at which the App Launcher will appear. You can adjust this within the Pearl App under General Settings > App Launcher> Delay:
  • RearVision also uses the CAN bus to detect when your speed decreases as you’re getting ready to park. This triggers a signal to prepare the system to start video quickly when you return to the Pearl App. So, if you have a car that doesn’t utilize CAN data, you may wish to launch the Pearl App about 15 seconds before you expect to use it. This ensures that RearVision is ready to go by “waking” the system back up.

Feel free to contact us if you need any additional clarification or help - and be sure to check out our related articles for more info!