Possible fault patterns during CURRENT CHECK test

No voltage or no current during the USB test

Fig 1: Display - Fault Patterns Current Check Test Screen

Courtesy of BMW OF NORTH AMERICA, INC.

The graphics shows the case if the USB cable has not been connected or the USB connection in the vehicle is not supplying any voltage. The current supplied by the vehicle (orange line) remains at 0mA and the voltage (green line) is not visible because it is below the range shown on the display.

Troubleshooting:

Check USB cable connection between IMIB and vehicle.
Check lines and plug connections in vehicle.
Check the USB connection.
Check control unit.
Check fuse F26.

Line resistance too high during USB test

Fig 2: Display - Line Resistance Too High During USB Test Screen

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 under 3.9 Volt at 500mA)

NOTE: With several USB devices, a voltage 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.

Overloading during the USB test

Fig 3: Display - Overloading During USB Test Screen

Courtesy of BMW OF NORTH AMERICA, INC.

The graphic shows a current limitation at approx. 300mA (1). The vehicle is not able to deliver the required level of current. Voltage level collapses and the current is therefore limited.

Troubleshooting:

The customer may have attached a USB hub (distributor) to the vehicle USB connection. Always run the USB test directly on the USB connection in the vehicle!
Check the USB connection.
Check lines and plug connections in vehicle.
Check control unit.

NOTE: If the test was not successful, a vehicle diagnosis must be carried out with ISTA!