Communication with the EMS control unit
Check whether the EMS control unit has generated any fault codes. If not: Check the connection between the red CAN bus and the EMS control unit. Check the EMS control unit supply voltage circuit (30) and the EMS control unit activation signal circuit (15). Check the red CAN bus cable harness and connectors. Measure the resistance between the coordinator's pin for CAN-High and CAN-Low of the red CAN bus with the battery disconnected. Resistance should be around 60 ohm. (Due to the two termination resistors connected in parallel.)
What you'll see
No driver-visible symptom recorded.
System reaction
No system-reaction text recorded.
Diagnostic depth
Communication between the coordinator and EMS control unit has been interrupted.
The fault may be due to: Fault in the EMS control unit connection to the red CAN bus. Short circuit or open circuit in the EMS control unit supply voltage. Internal fault in the EMS control unit.