E54
Low/High Pressure Sensor Disconnection/Output Error
Mitsubishi Electric · FR-D700 Inverter
What does E54 mean?
This error indicates a disconnection or output error with either the low-pressure sensor (PSL) (E54-1) or the high-pressure sensor (PSH) (E54-2). This prevents accurate pressure monitoring, jeopardizing system safety and control.
Common Causes
- Disconnection of the low or high-pressure sensor.
- Pressure sensor outputting an invalid signal, possibly due to internal failure.
- Faulty wiring harness between the pressure sensor and the control board.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Check the low-pressure sensor (PSL) and high-pressure sensor (PSH) connections for security and physical damage.
- 2
Measure the output voltage or resistance of both PSL and PSH sensors and compare to specification.
- 3
Verify the wiring continuity from the sensors to the outdoor unit PCB, checking for breaks or short circuits.
Verified technical data. Last updated: March 2026
Related Faults
Source: Mitsubishi Electric FR-D700 Inverter