Mitsubishi Electric aircon UP error code & blinking light
Use this Mitsubishi Electric UP guide to capture the fault correctly and see what should be checked before parts are quoted. Match the model first; same-looking signals can point to different rows.
What does Mitsubishi Electric UP mean?
Mitsubishi Electric UP is listed as compressor overcurrent interruption, outdoor power system, and compressor overcurrent, current sensor abnormality, or power module abnormality in Ceiling Cassette, Ceiling Concealed Ducted, Ceiling Suspended rows such as PLY-ZM / PLY-M cassette, PEY-M JAL ceiling-concealed ducted. The loaded row is source-backed by official diagnostic material. Do not collapse this code across model families; use the model, series, or system type to choose the right row. Confirm the exact model, series, or signal row before accepting a parts quote.
Choose the matching source row
The same visible code has more than one source-backed meaning. Match the model family, system type, or reporting unit before approving parts.
| Code | What it means | What to check first |
|---|---|---|
| PLY-ZM / PLY-M cassette | Compressor overcurrent interruption | Match this row to the installed model or reporting unit, then use the source-specific checks below. |
| SUY-KA / SUY-ZM / SUY-M outdoor LED table | Outdoor power system | Match this row to the installed model or reporting unit, then use the source-specific checks below. |
| PUY-P / PUY-M outdoor LED table | Compressor overcurrent, current sensor abnormality, or power module abnormality | Match this row to the installed model or reporting unit, then use the source-specific checks below. |
What to do now
Use these steps before customer action or a parts quote.
Stop using the unit if UP returns
Stop repeated restarts if UP returns; compressor and inverter faults can become more expensive when forced to run.
No manufacturer reset steps listed for UP
Capture the complete UP pattern and model stickers first. The selected source row lists no customer reset procedure; do not treat a generic power-cycle as manufacturer guidance.
Send these to us
UP error code and blinking light, a clear display photo and blinking-light video if the unit shows one, Mitsubishi Electric model stickers, affected rooms, operating state when the code appeared, and trip timing and outdoor-unit behaviour
Source-specific guidance
These diagnostic-reference notes help match the code to the exact model. Electrical, refrigerant, wiring, resistance, and component checks are technician work, not DIY steps.
| Source detail | What it says |
|---|---|
| Diagnostic note | Stop repeated resets. Check compressor wiring, inverter circuit, stop valves, and compressor resistance. |
| Diagnostic note | Check compressor connector, inverter, compressor, and stop valve before resetting. |
| Diagnostic note | Check stop valves, compressor wiring, compressor resistance, and outdoor-air short cycling. |
| Singapore / model note | Official Mitsubishi Electric Singapore Mr Slim PDF page 4, Output pattern B. Use only for the listed PLY cassette, PEY ceiling-concealed ducted, and PCY ceiling-suspended indoor models; confirm the paired outdoor model before parts replacement. |
| Singapore / model note | Official Mitsubishi Electric Singapore Mr Slim PDF page 5, SUY outdoor LED table. Match this only to the listed Mr Slim outdoor model family and confirm the paired indoor model before parts replacement. |
| Singapore / model note | Official Mitsubishi Electric Singapore Mr Slim PDF page 10, PUY outdoor LED table. Match this only to the listed Mr Slim outdoor model family and confirm the paired indoor model before parts replacement. |
What to check before repair
Use this split to separate safe evidence capture from the tests a technician should prove before quoting parts.
| You can check | Technician should confirm |
|---|---|
| Before taking any system action on UP, take a clear display photo and blinking-light video if the unit shows one. | Confirm whether UP is compressor start, overload, lock, or drive protection. |
| Capture the Mitsubishi Electric indoor and outdoor model stickers so the correct family row is used. | Check supply voltage, inverter output, IPM status, compressor current, and winding readings. |
| The selected source row lists no customer reset procedure. Note whether one room, several rooms, or the whole system is affected. | Review trip history and compressor mechanical signs before quoting replacement. |
Compressor drive or replacement decision
Mitsubishi Electric UP can still be a repair if power, inverter, or module checks find the cause. Compressor replacement should be weighed against age, warranty, and the rest of the system condition.
Inverter or IPM faults are not the same as confirmed compressor mechanical failure.
Compressor winding and current readings should be measured before replacement is discussed.
Older systems need a repair-versus-replace check if compressor-side parts are expensive.
Mitsubishi Electric UP questions
What does the Mitsubishi Electric UP error mean?
Can I fix a Mitsubishi Electric UP error myself?
Is it safe to keep running the aircon with a UP error?
What causes a Mitsubishi Electric UP error?
Will a Mitsubishi Electric UP error need a repair or a full replacement?
What should I send a technician about a Mitsubishi Electric UP error?
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Use these if the quote mentions the parts, checks, or repair path this code points to.