Scania COO DTC 66 Communication with the AWD control unit

COO Coordinator · Scania

Code 66 (decimal). Some diagnostic tools show it in hexadecimal as 0042.

In short

The communication between the coordinator and the AWD control unit has been interrupted.

Applies to: COO6 (COO6C)

What does Scania COO fault code 66 mean?

The communication between the coordinator and the AWD control unit has been interrupted.

What causes Scania DTC 66?

The fault may be due to: - Open circuit in the yellow CAN bus - Short circuit or open circuit in the AWD control unit power supply - Internal fault in the AWD control unit.

How does the system react?

There may be a problem activating or deactivating the differential locks as long as the fault is active.

How to fix Scania COO fault code 66?

  1. Check the yellow CAN bus cabling and harness-to-harness connectors.
  2. Check the AWD control unit voltage supply circuit (30) and also the AWD control unit activation signal circuit (15).
  3. You can see whether the AWD control unit has generated any fault codes via the instrument cluster.

This information is for guidance only. Always follow the manufacturer workshop manual and safety procedures; if in doubt, contact an authorised workshop.

Code 66 in other Scania systems

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