The reason why music cannot be played when the Cadillac ats is connected via Bluetooth: the audio source is not selected as Bluetooth, only the audio source is selected as Bluetooth. Specific steps for connecting the car Bluetooth to the mobile phone: 1. Turn on both the mobile phone Bluetooth and the car Bluetooth and make them discoverable; 2. Search for the car Bluetooth on the Bluetooth interface of the mobile phone; 3. Select the car Bluetooth displayed on the mobile phone and click on the car Bluetooth interface. For Bluetooth pairing, click Pair on the car Bluetooth interface at the same time; 4. After the pairing code is entered correctly, it will be displayed on the car Bluetooth as connected after a while; 5. Select the automatic connection function on the car Bluetooth setting interface. After that, if the phone and the car If Bluetooth is turned on and the range is within 10 meters, automatic connection will be achieved. Cadillac ATs is a sports mid-level sedan under Cadillac. The length, width and height of Cadillac ATS are 4730mm, 1824mm, 1426mm respectively, and the wheelbase is 2860mm. Its front suspension adopts double ball joint independent suspension, and the rear suspension adopts multiple Link independent suspension. All Cadillac ATs series use a 2.0-liter turbocharged engine. This engine has 279 horsepower and a maximum torque of 400 Nm. This engine is matched with an 8AT gearbox.