CAN bus
â–¶ How to fix
Check wiring for short circuits and open circuits.Check the CAN bus, see Communication problems under Help.Check whether other control units have lost contact with the tachograph.
What you'll see
No driver-visible symptom recorded.
System reaction
No system-reaction text recorded.
Diagnostic depth
Detection
Expected CAN-message from EMS missing.
Possible cause
The fault can be caused by one of the following EMS does not send or COO is inoperative.CAN communication interrupted.Short circuit between CAN High and CAN Low.CAN High short circuited to positive or earth.CAN Low short circuited to positive.