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Error code reference

Mitsubishi Air Conditioner Error Code UF

USB host error

Mitsubishi codesMitsubishi air conditioner codes
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What the UF error code actually means

Your Mitsubishi air conditioner has detected that something connected to its USB port is drawing too much power, which could damage the unit. This usually happens when a phone charger, USB hub, or other non-memory device is plugged into the USB slot instead of a simple USB flash drive. Remove whatever is plugged into the USB port and restart the unit to clear the error.

Diagnostic procedure

The full UF procedure

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1
First diagnostic step
Check if a USB device other than a USB memory device is connected to the USB A connector.
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Most common causes of UF

Ranked by how often they cause this code
  1. 1Incompatible USB device connected
  2. 2Faulty or damaged USB memory device
  3. 3Damaged USB Type-A port on the control board
  4. 4Failed USB host controller on the main PCB

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Questions people ask about UF

What does UF mean on a Mitsubishi air_conditioner?
UF is a USB host error indicating that excessive current is flowing into the USB Type-A connector on the unit. The port is intended only for USB memory devices, and connecting an incompatible or power-hungry device will trigger this fault. The system flags this error to protect the USB host controller circuitry from damage.
Will resetting my Mitsubishi air conditioner clear the UF error?
A power reset may temporarily clear the UF fault code, but the error will return if the underlying cause has not been addressed. You must first remove or replace the connected USB device before cycling power. If the fault is caused by a damaged port or control board component, resetting alone will not resolve it.
How much does it cost to repair a UF error on a Mitsubishi air conditioner?
If the issue is simply an incompatible USB device, there is no repair cost beyond replacing the USB flash drive, which typically costs between $5 and $20. If the main control board has been damaged and requires replacement, repair costs including parts and labor can range from $300 to $700 or more depending on the unit model and service rates in your area.
How do I fix the UF error on my Mitsubishi air conditioner?
Start by unplugging any device connected to the USB-A port on the unit. If the connected device was not a standard USB flash drive, replacing it with a compatible USB memory stick should resolve the issue. If the error persists after removing all USB devices, the USB port or control board may have sustained damage and will require inspection by a technician.
Is the UF error on a Mitsubishi air conditioner dangerous?
The UF error itself is a protective fault, meaning the unit has already detected the overcurrent condition and stopped it from causing immediate harm. Continuing to operate the unit with a faulty USB device or damaged port connected could risk damage to the control board over time. Addressing the cause promptly is recommended to avoid more costly repairs.

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