Final answer:
The probable causes for the Uconnect 4 system not launching Android Auto are a faulty USB cable, non-functioning vehicle USB port, absence of the Android Auto app on the phone, or outdated Uconnect software.
Step-by-step explanation:
The probable cause for the customer's Uconnect 4 system not launching Android Auto when the phone is connected could be a faulty USB cable, a non-functioning vehicle USB port, or the absence of the Android Auto app on the phone. Additionally, it is also possible that the Uconnect software needs an update. To troubleshoot the issue, the customer should try using a different USB cable, test a different device on the vehicle USB port, check if Android Auto is installed and updated on the phone, and ensure that the Uconnect software is up to date.