“No vehicle CAN activity on MSB” fault on display

Check no engine lights on vehicle / speedometer work.

Check CAN line Voltages to MSB as per diagnostic guide.

Check DIP switch 3 set to ON as per diagnostic guide.

Check CAN Display connector not connected to screen harness. Refer to schematic; check that VEH CAN not ticked in screen setting menu. 

This would be most likely if this was a new install or replacement, not out in the field.

MSB ECU has failed. This option is unlikely, but possible. Refer to all steps in the diagnostic guide to confirm.

Welding or jumpstarting etc may over voltage the ECU causing damage.

For full list of diagnostic steps refer to MSARB Diagnostic Troubleshooting Guide – Speed Signal.