What does a higher than normal ohmmeter reading across the J1939 backbone typically indicate?

A higher than normal reading on an ohmmeter across the J1939 backbone generally indicates high resistance in the CAN stubs. In a J1939 network, which is commonly used for communication in heavy-duty vehicles, the backbone should exhibit a specific resistance value that reflects the proper functioning of its connections and components.

When the reading is higher than expected, it suggests that there may be an issue with the connections, such as corrosion or damaged wiring, which increases resistance and can lead to communication problems between modules. High resistance could hinder the flow of electrical signals across the network, potentially causing intermittent faults or a complete failure in communication.

This high resistance reading can be a precursor to diagnosing issues within the system, prompting further investigation into the integrity of the CAN stubs and the overall connectivity of the J1939 backbone.