Code 54
Onan CAN Bus Communication Error

Generator shuts down; Code 54 displayed indicating CAN communication fault (on newer digital models)

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Loose or damaged CAN harness between controller and modules, Incorrect termination resistors, Electrical noise or grounding issues, Failed controller or remote module

How to Fix / Troubleshooting

Safety first: Disable auto-start and open the main breaker. Work with power off when handling communication wiring.

  • Inspect CAN wiring: Trace the twisted-pair CAN wires between the Onan controller, remote display, and any other modules. Look for pinched, cut, or abraded insulation.
  • Check connectors: Reseat all CAN connectors. Look for bent pins or corrosion.
  • Verify termination: Ensure that termination resistors are installed only at the ends of the CAN bus as specified by Onan. Incorrect termination can cause communication errors.
  • Grounding: Confirm that all modules share a solid common ground. Correct any loose ground connections.
  • Module isolation: Disconnect non-essential modules one at a time to identify a faulty device causing bus errors.
Advertisements

Repair Difficulty

Hard 4/5

Required Part

Control Harness (CAN Bus Wiring)
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements