Independent motion signal fault
* Check for DTCs in systems(ABS/EBS) distributing the independent motion signal (EBC2:FrontAxelSpeed). * Check if there is CAN communication problems with other ECU:s on the same CAN bus. * Check CAN communication/gateway in COO. * Check the tachograph A connector, and pin assignment: - Pin A4: CAN high. - Pin A7: CAN ground. - Pin A8: CAN low.
What you'll see
No driver-visible symptom recorded.
System reaction
MC81/EV306: * Warning message with error text: "IMS fault" together with Memory Code 81 is displayed in the tachograph display. * The warning message will be displayed repetitively every hour until the cause is withdrawn. * Event stored in the tachograph memory * Event stored and in the inserted tachograph card. * System event in TCO1 CAN message is set to active. * Tachograph warning (amber T) is displayed in the instrument cluster.
Diagnostic depth
The additional independent motion signal (EBC2:FrontAxelSpeed from the ABS/EBS system) is missing or is not available
* Fault in the CAN bus medium * Fault in the ABS/EBS system * Fault in the CAN gateway by COO