Line resistance too high during USB test

Fig 1: Line Resistance Versus High USB Test Graph

Courtesy of BMW OF NORTH AMERICA, INC.

The curve progression on the green line (1) drops off significantly in the graphic that is displayed. (Voltage less than 3.9 V at 500 mA)

NOTE: With several USB devices, a voltage of around 4 V is not sufficient to guarantee the function. However, the vehicle is trouble-free! In this case, use a different USB device.

Troubleshooting:

Check USB cable connection between IMIB and vehicle (use spare cable from another IMIB if necessary).
Check the USB connection.
Check lines and plug connections in vehicle.