Mitsubishi fault codes
8 codes from Mitsubishi plates on FieldBench. Same number on another maker is a different code.
Diagnose a Mitsubishi call
The list stays open.
- Lockout
E8 / U2
Overcurrent / high load
Compressor or outdoor protection.
3 plates
- Lockout
EA
4-way valve
Did not shift or sensor disagrees.
3 plates
- Protect
F3
Discharge thermistor
Outdoor discharge.
3 plates
- Protect
P1 / P2
Indoor thermistors
Return or pipe sensor.
2 plates
- Lockout
P4 / P9
Drain / float
Cassette/ducted more than wall, but FS can still show a drain accessory fault.
1 plate
- Protect
P6
Freeze / overheat
Coil out of band.
2 plates
- Lockout
Pressure protect
High / low pressure protect
Outdoor high- or low-pressure protection (token is on the MXZ door card for this revision — do not invent a City Multi number).
1 plate
- Lockout
U4
Communication
Indoor–outdoor transmission.
3 plates