Daikin VRV

Daikin VRV Error Code UJ

Troubleshooting guide for the Daikin VRV system fault UJ.

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What It Means

Malfunction of transmission (accessory device).

Possible Causes

  • Defect of accessory devices.
  • Faulty wiring.

Not sure which one it is — or if it's none of these? Try ACLogics today.

Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.
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Full Diagnosis

Malfunction of transmission (accessory device)

All Recorded Causes

Defect of accessory devices Faulty wiring

Verify Before Replacing Parts

  1. Confirm the exact Daikin model family and vrv context before acting on a generic code description.
  2. Start with line voltage, low voltage, and board output checks in sequence so the fault is isolated cleanly — the data plate flags defect of accessory devices.
  3. Inspect connectors, relay outputs, and any recently replaced electrical parts for mismatch or loose fit, and verify faulty wiring.
  4. After the correction, run the system long enough to confirm the vrv fault does not return under normal load.

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