A diesel excavator is exhibiting intermittent communication errors on its display panel and diagnostic tool. The technician suspects a problem with the CAN-bus. Using a multi-meter, the technician measures the resistance between CAN High and CAN Low wires with the ignition off and all modules disconnected from the bus. What resistance value should the technician expect to see across these two wires on a properly terminated CAN-bus segment?

Question: A diesel excavator is exhibiting intermittent communication errors on its display panel and diagnostic tool. The technician suspects a problem with the CAN-bus. Using a multi-meter, the technician measures the resistance between CAN High and CAN Low wires with the ignition off and all modules disconnected from the bus. What resistance value should the technician expect to see across these two wires on a properly terminated CAN-bus segment?

Answer options: ✅ Approximately 60 Ohms.

• Approximately 120 Ohms.
• Approximately 0 Ohms (a short circuit).
• Infinite Ohms (an open circuit).

Correct answer: Approximately 60 Ohms.

Explanation: A properly terminated CAN-bus segment uses two 120 Ohm resistors, one at each end of the bus. When measured in parallel across CAN High and CAN Low with the ignition off and no modules actively sending signals, the total resistance should be approximately 60 Ohms (120 || 120 = 60). Open or short circuits would indicate a faulty bus line or terminations.