Communication with the AWD control unit
Check whether the AWD control unit has generated any fault codes. If not: Check the connection between the yellow CAN bus and the AWD control unit. Check the AWD control unit supply voltage circuit (30) and also the AWD control unit activation signal circuit (15). Check the yellow CAN bus cable harness and connectors. Measure the resistance between the coordinator's pin for CAN-High and CAN-Low of the yellow 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 coordinator and AWD control unit has been interrupted.
The fault may be due to: Short circuit or open circuit in the AWD control unit supply voltage circuit. Internal fault in the AWD control unit. Open circuit in the yellow CAN bus.