General Assist Technical Reference
Mobile Technician App - Error Codes
Indoor LED flash patterns and wired remote controller error codes
Reference for RAC / PAC systems and selected VRF accessories
The Mobile Technician App identifies faults using the indoor unit LED flash pattern or the error code displayed on a wired remote controller. Use the tables below to match the Operation and Timer lamp flash counts with the corresponding error detail and wired RC code.
Important: The source reference lists the fault indication and code only. It does not provide diagnostic test procedures, component replacement instructions or confirmation that a listed component is defective. Complete the appropriate service diagnosis before replacing parts.
How to read the fault indication
- Count the number of flashes from the indoor unit Operation lamp.
- Count the number of flashes from the Timer lamp.
- For the listed faults, the Economy lamp indication is shown as Continuous.
- Match the flash pattern to the table below. If a wired remote controller is fitted, the equivalent Wired RC code is also shown.
Example: Operation lamp 7 flashes + Timer lamp 1 flash + Economy lamp Continuous = OU discharge temperature sensor error, Wired RC code 71.
RAC / PAC error code reference
| Error detail | Operation | Timer | Economy | Wired RC |
|---|---|---|---|---|
| Serial communication error | 1 | 1 | Continuous | 11 |
| Wired RC communication error | 1 | 2 | Continuous | 12 |
| Network communication error | 1 | 4 | Continuous | 14 |
| Check run unfinished | 1 | 5 | Continuous | 15 |
| Transmission/Peripheral connect error | 1 | 6 | Continuous | 16 |
| Refrigeration circuit address setting error | 2 | 1 | Continuous | 21 |
| Indoor unit capacity error | 2 | 2 | Continuous | 22 |
| Combination error | 2 | 3 | Continuous | 23 |
| Connection unit number error | 2 | 4 | Continuous | 24 |
| Address setting error | 2 | 6 | Continuous | 26 |
| Master/Slave unit set-up error | 2 | 7 | Continuous | 27 |
| Connection unit number error in WRC circuit | 2 | 9 | Continuous | 29 |
| Power supply interruption error | 3 | 1 | Continuous | 31 |
| Indoor PCB EEPROM error | 3 | 2 | Continuous | 32 |
| Manual auto switch error | 3 | 5 | Continuous | 35 |
| Indoor unit WRC communication error | 3 | 10 | Continuous | 3A |
| Inlet air temp sensor error | 4 | 1 | Continuous | 41 |
| Indoor Heat-Ex middle temp sensor error | 4 | 2 | Continuous | 42 |
| Indoor unit fan motor error | 5 | 1 | Continuous | 51 |
| Indoor EEV error | 5 | 2 | Continuous | 52 |
| Drain pump error | 5 | 3 | Continuous | 53 |
| Damper error | 5 | 7 | Continuous | 57 |
| Intake grille error | 5 | 8 | Continuous | 58 |
| Indoor unit error | 5 | 15 | Continuous | 5U |
| Outdoor PCB/communication error | 6 | 2 | Continuous | 62 |
| Inverter error | 6 | 3 | Continuous | 63 |
| Active filter/PFC circuit error | 6 | 4 | Continuous | 64 |
| Trip terminal 'L' error | 6 | 5 | Continuous | 65 |
| Display PCB/communication error | 6 | 10 | Continuous | 6A |
| OU Discharge temp sensor error | 7 | 1 | Continuous | 71 |
| Compressor temp sensor error | 7 | 2 | Continuous | 72 |
| OU Heat-Ex liquid temp sensor error | 7 | 3 | Continuous | 73 |
| OU Ambient temp sensor error | 7 | 4 | Continuous | 74 |
| OU Suction ref temp sensor error | 7 | 5 | Continuous | 75 |
| 2/3 way valve temp sensor error | 7 | 6 | Continuous | 76 |
| OU Heat sink temp sensor error | 7 | 7 | Continuous | 77 |
| Sub-cool inlet/outlet temp sensor error | 8 | 2 | Continuous | 82 |
| OU Liquid pipe temp sensor error | 8 | 3 | Continuous | 83 |
| OU current sensor error | 8 | 4 | Continuous | 84 |
| HP/LP pressure sensor/switch error | 8 | 6 | Continuous | 86 |
| OU Current trip detection | 9 | 4 | Continuous | 94 |
| Compressor rotor location detection error | 9 | 5 | Continuous | 95 |
| OU fan motor error | 9 | 7 | Continuous | 97 |
| OU fan motor 2 error | 9 | 8 | Continuous | 98 |
| 4-way valve error | 9 | 9 | Continuous | 99 |
| Coil (expansion valve) error | 9 | 10 | Continuous | 9A |
| Outdoor unit error | 9 | 15 | Continuous | 9U |
| OU Abnormal discharge temp error | 10 | 1 | Continuous | A1 |
| Abnormal compressor temp error | 10 | 3 | Continuous | A3 |
| High Pressure error | 10 | 4 | Continuous | A4 |
| Low pressure error | 10 | 5 | Continuous | A5 |
| VRF Branch box error | 13 | 1 | Continuous | J1 |
| 8-Way Multi branch box error | 13 | 2 | Continuous | J2 |
VRF branch box and wired controller accessory indications
| Accessory / Error detail | PCB LED (Green) | PCB LED (Red) | WRC |
|---|---|---|---|
| VRF RB: Cable crossed OU/RB - IU/RB | On solid | On solid | - |
| VRF RB: Comms/Main PCB error | On solid | Continuous | - |
| WRC: Incompatible IU connected | - | - | C0:15 |
| WRC: Indoor - WRC comms error | - | - | C0:12 |
Mobile Technician App functions shown in the source reference: RAC / PAC and VRF type selection, LED flash-count identification, reference documentation and thermistor value conversion.
Source: Mobile Technician App error code reference, Fujitsu General Limited.