Low Pressure Sensor (PSL) Disconnection/Output Error

What does E54-1 mean?

The low-pressure sensor (PSL) is either disconnected or its output signal is erroneous, indicating a fault in the sensor or its connection to the system. This specifically refers to the PSL.

• Low pressure sensor (PSL) connection is lost or wiring is damaged.
• The PSL sensor is reporting an error or has failed electronically.
• Inconsistent readings from the PSL sensor compared to expected operating parameters.

Click steps to track your progress.

1. 1

   Inspect the PSL sensor's connector on the outdoor unit PCB — verify it is securely seated.

2. 2

   Measure the output voltage or resistance of the PSL sensor according to manufacturer specifications using a multimeter.

3. 3

   Check continuity of the wiring connecting the PSL sensor to the PCB.