E38

Outside Air Temperature Sensor (ThoA) Defective / Poor Connection

Mitsubishi Electric · Mitsubishi FR-D700 Inverter

What does E38 mean?

The outside air temperature sensor (ThoA) is defective (open circuit resistance) or has a poor connection on the outdoor unit PCB. This compromises the system's ability to accurately sense ambient conditions and adjust operation.

Source: Mitsubishi FR-D700 Inverter

Open Manual (Page 4)