DTC B1252-19: USB Port - Circuit current above threshold: Action

NOTE: If this DTC is logged, this suggests that the universal serial bus port has been overloaded, by a portable device or faulty cable

Confirm universal serial bus port operation, and using the manufacturer approved diagnostic system, check the integrated audio module for related DTCs and refer to the relevant DTC index
Disconnect all the universal serial bus connected devices. Close all the doors and lock the vehicle, wait for a few minutes (to shut down the media orientated system transport ring). Restart the vehicle and check if the universal serial bus operation has recovered
Using the manufacturer approved diagnostic system, clear the DTCs and retest. Advise the customer of the use of faulty devices/cables. Some devices will draw more current when charging such as iPads and can cause this DTC to log. This is not a permanent fault