# Mitsubishi Electric Mr. SLIM (PLY / PEY / PCY), Singapore error codes

URL: https://costolio.com/home/appliances/mitsubishi-electric/mitsubishi-electric-mr-slim-ply-pey-pcy-singapore-list-sg-models/
Updated: 2026-11-02

# Mitsubishi Electric Mr. SLIM (PLY / PEY / PCY), Singapore list (-SG models) error codes

11 heat pump / mini-split error codes for Mitsubishi Electric Mr. SLIM (PLY / PEY / PCY), Singapore list (-SG models), what each one means and what to try, paraphrased from Mitsubishi Electric's own source. Codes vary by model, so confirm in your own manual.

## All codes

- [P1](https://costolio.com#p1) Intake sensor error.
- [P2 / P9](https://costolio.com#p2-p9) Pipe (TH2) or pipe (TH5) sensor error.
- [E6 / E7](https://costolio.com#e6-e7) Indoor-outdoor communication error.
- [P4](https://costolio.com#p4) Drain float switch connector open.
- [P6](https://costolio.com#p6) Freeze protection (cooling) or overheat protection (heating) operated.
- [P8](https://costolio.com#p8) Pipe temperature error.
- [PL](https://costolio.com#pl) Refrigerant circuit abnormal.
- [U2](https://costolio.com#u2) High discharge temperature or not enough refrigerant.
- [UP](https://costolio.com#up) Compressor overcurrent interruption.
- [UF](https://costolio.com#uf) Compressor overcurrent because the compressor is locked.
- [U1 / Ud](https://costolio.com#u1-ud) Abnormal high pressure or overheat protection.

## P1

What it means: Intake sensor error. This one often needs a licensed technician.

### What to try

- Call a Mitsubishi Electric service technician.

## P2 / P9

What it means: Pipe (TH2) or pipe (TH5) sensor error. This one often needs a licensed technician.

### What to try

- Call a Mitsubishi Electric service technician.

## E6 / E7

What it means: Indoor-outdoor communication error. This one often needs a licensed technician.

### What to try

- Call a Mitsubishi Electric service technician.

## P4

What it means: Drain float switch connector open. This one often needs a licensed technician.

### What to try

- Call a Mitsubishi Electric service technician.

## P6

What it means: Freeze protection (cooling) or overheat protection (heating) operated. This one often needs a licensed technician.

### What to try

- Call a Mitsubishi Electric service technician.

## P8

What it means: Pipe temperature error. This one often needs a licensed technician.

### What to try

- Call a Mitsubishi Electric service technician.

## PL

What it means: Refrigerant circuit abnormal. This one often needs a licensed technician.

### What to try

- Call a Mitsubishi Electric service technician.

## U2

What it means: High discharge temperature or not enough refrigerant. This one often needs a licensed technician.

### What to try

- Call a Mitsubishi Electric service technician.

## UP

What it means: Compressor overcurrent interruption. This one often needs a licensed technician.

### What to try

- Call a Mitsubishi Electric service technician.

## UF

What it means: Compressor overcurrent because the compressor is locked. This one often needs a licensed technician.

### What to try

- Call a Mitsubishi Electric service technician.

## U1 / Ud

What it means: Abnormal high pressure or overheat protection. This one often needs a licensed technician.

### What to try

- Call a Mitsubishi Electric service technician.

### Source

- [Mr. SLIM error codes, PLY/PEY/PCY (Mitsubishi Electric Singapore)](https://www.mitsubishielectric.com.sg/getmedia/2d5c4795-7b48-4a89-adff-ae5589e21020/MrSlimErrorCode-V2.pdf) (checked 2026-11-02)

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