Mitsubishi Error Code U2: Low Voltage/Overcurrent
Warning: Your Mitsubishi HVAC system has detected a low voltage or overcurrent issue, which could damage components. Shut down the system and call a professional for repair.
LED Blink Pattern
How to Fix Mitsubishi Code U2
- Step 1: Turn off the system at the thermostat and the circuit breaker.
- Step 2: Do not attempt to open the unit or touch any electrical components.
- Step 3: Call a professional HVAC technician for repair.
How to Reset Mitsubishi Code U2
- Turn off the unit using the remote control or wall controller.
- Turn off the circuit breaker for the outdoor and indoor units. Wait 60 seconds.
- Restore power at the breaker.
- Turn the unit on with the remote control. If the error returns, the fault needs professional diagnosis.
Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.
What Does Mitsubishi Error Code U2 Mean?
The U2 error code on your Mitsubishi HVAC system indicates a low voltage or overcurrent issue. This could be due to a faulty component drawing too much power or a wiring problem. The system has entered a protective mode to prevent further damage. It's important to address this issue promptly to avoid potential damage to your system.
Common Causes
- Faulty compressor or fan motor
- Wiring issue or short circuit
- Overloaded circuit
- Faulty control board
Diagnostic Steps
| If... | Check | Expected |
|---|---|---|
| System is not running | Measure voltage at the control board's power terminals | 120V AC |
| System is running | Inspect wiring for any visible damage or shorts | No damage or shorts |
| Compressor or fan motor is running | Measure amperage draw | Within manufacturer's specified range |
Applicable Mitsubishi Models
- City Multi (VRF)(electric)
- City Multi (Y)(electric)
- Diamond (PJ)(electric)
- Diamond Plus(electric)
- Diamond Series(electric)
- Ducted Systems(electric)
- M-Series(electric)
- MSZ(electric)
- MSZ Series(electric)
- MSZ-AP(electric)
- MSZ-AP Series(electric)
- MSZ-AP5 Series(electric)
- MSZ-AS(electric)
- MSZ-FD(electric)
- MSZ-FE(electric)
- MSZ-FS(electric)
- MSZ-FS/FD Series(electric)
- MSZ-FT(electric)
- MSZ-FY(electric)
- MSZ-GE(electric)
- MSZ-LV(electric)
- MUZ-FE Series(electric)
- P-Series(electric)
- PUMA(electric)
- PUMY(electric)
- Puff (P-Series)(electric)
Replacement Parts
| Part | OEM Number | Est. Cost | Where to Buy |
|---|---|---|---|
| Compressor | 530-00001-000 | — | Find Part |
| Control Board | 530-00002-000 | — | Find Part |
| Wiring Harness | — | — | — |
Related Codes on Same Models
Other codes that affect the same Mitsubishi model families as U2.
| Code | Description | Severity |
|---|---|---|
| 1 | Indoor/Outdoor Mismatch | Warning |
| 2 | Power Supply Phase Error | Warning |
| 4 | Inverter Error | Warning |
| 7 | Outdoor Freeze/Overheat | Warning |
| E6 | Indoor/Outdoor Communication Error | Warning |
| E9 | Indoor/Outdoor Communication Fault | Warning |
| P2 | Indoor Pipe Thermistor Error | Warning |
| P4 | Drain Sensor Error | Warning |
| P6 | Coil Freeze/Overheat Protection | Warning |
| U3 | Discharge Thermistor Short/Open | Warning |