A hidden feature in these Pokémon games is the ability to tell a certain NPC four specific words or phrases using the easy chat system in order to unlock special rewards. Which words are required are unique per save file.
In Diamond, Pearl, and Platinum these rewards include 8 different special PC box wallpapers. The NPC to speak to is located on the 3rd floor of the Jubilife TV station.
In HeartGold and SoulSilver, rewards include 8 different PC box wallpapers plus 3 different Pokémon eggs. The NPC to speak to is located in the Violet City Pokémon Center.

The original distribution of these passwords was via the Pokémon Daisuki Club, a defunct, Japanese-exclusive official fan club website.
Below is both a calculator to generate the passwords for your specific save file, an in-depth explanation of how the password check system functions, and a full dump of the relevant word data.
| LED Indication (Operation/Timer) | Error Code | Cause | Solution | |----------------------------------|------------|-------|----------| | 1 blink / 1 blink | P1 | Indoor room thermistor open/short | Check RT11 (2–15 kΩ) | | 1 blink / 2 blinks | P2 | Indoor pipe thermistor open/short | Check RT12 | | 2 blinks / 1 blink | E6 | Indoor/Outdoor communication error | Check TB3-3 voltage (pulsed 0–24V). Verify wiring polarity. | | 3 blinks / 1 blink | E0 | Outdoor control board – EEPROM error | Replace outdoor PCB | | 3 blinks / 2 blinks | E1 | Outdoor thermistor (RT61/62) fault | Check resistance vs temp chart | | 4 blinks / 2 blinks | F3 | Discharge pipe temp > 110°C | Low refrigerant, LEV stuck closed, or overcharge | | 5 blinks / 1 blink | F1 | High pressure switch triggered | Blocked outdoor coil, fan failure, overcharge | | No blinks / 2 blinks | U2 | Compressor overcurrent / lock | Check compressor windings, inverter module |
This text is for informational purposes only. Always refer to the official Mitsubishi Electric Service Handbook (OCH###) for proper safety procedures, wiring verification, and troubleshooting. Service Manual: Mitsubishi MSY-GE10VA Type: Wall Mounted, Heat Pump, Inverter Split System Refrigerant: R410A Power Supply: 230V ~ 50Hz (Single Phase) 1. Technical Specifications | Parameter | Cooling | Heating | |-----------|---------|---------| | Capacity (Min-Rated-Max) | 1.0 kW – 2.5 kW – 3.2 kW | 1.1 kW – 3.2 kW – 4.0 kW | | Power Input | 0.48 kW | 0.70 kW | | Running Current | 2.2 A | 3.1 A | | EER/COP | 5.21 | 4.57 | | Moisture Removal | 1.2 L/h | – | | Airflow (Low-Mid-High) | 312 – 366 – 486 m³/h | 330 – 390 – 516 m³/h | | Operating Range (Outdoor) | -10 to 46°C DB | -15 to 24°C WB | | Noise Level (Indoor) | 21 – 29 – 40 dB(A) | 21 – 31 – 41 dB(A) | mitsubishi msy-ge10va service manual