The Jensen Heavy Duty CAN-bus Stereo, No. JCV2015BT, offers rear sleeper controls and automatic front-panel dimming to match dashboard illumination settings. Bluetooth integration gives the driver hands-free command of the stereo and mobile device. Drivers can answer phone calls and control music apps directly from their steering wheel. The stereo automatically mutes all other audio when incoming messages are being relayed. Once the message has been received in full, the stereo resumes. The Sirius-XM-ready system comes equipped with front panel access to USB, iPod and iPhone integration and charging, a 3.5mm input, a rear RCA auxiliary input and a seven-channel NOAA weatherband tuner.
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From Wikipedia, the Controller Area Network (CAN) bus is a "vehicle bus standard designed to allow microcontrollers and devices to communicate with each other within a vehicle without a host computer." These devices can also be referred to as electronic control units (ECUs). Essentially the CAN bus is a bunch of linked ECUs within the vehicle that communicate with each based on a broadcast. Every ECU intercepts every broadcast, but individually decide whether or not to react to it.