B124C Code: Meaning, Causes, and Symptoms | OBD2 Codes

B124C – USB2 Circuit


B124C Possible Symptoms


Engine Light ON (or Service Engine Soon Warning Light)


B124C Possible Causes


Faulty USB Port,USB Port harness is open or shorted,USB Port circuit poor electrical connection


B124C Description


The infotainment system has a USB port and SD card reader slot located in the center console. The USB port and the card reader slot interface with a hub device, internal to the auxiliary jack, USB, and memory card receptacle assembly. The auxiliary jack, USB, and memory card receptacle assembly receives fused battery voltage and ground from the harness to power the internal hub device as well as providing additional amperage to power USB devices. The internal hub device interfaces directly with the human machine interface control module via a standard USB cable. A Mini type USB connector is used to connect the cable at the USB port and at the human machine interface control module and at the auxiliary jack, USB, and memory card receptacle. Standard USB male to female connections are typically used for connecting USB cables together where an in-line connection is required. An in-line cable connection is typically found between the console and I/P harness. The USB port allows connectivity to the infotainment system from portable media players or a USB storage device (memory stick/ flash drive). When a device is connected to the USB port, the system detects the device and switches to USB as the audio source. Once connected, the device can be controlled from the radio controls. The infotainment uses the SD card reader as a mass storage device, similar to a USB storage device.