Samsung AM072FXVAFH series Service Manual page 283

Test Operation
3) High / Low pressure sensor (Module installed)
High/Low Pressure sensor of each of the outdoor unit that module is installed.
Error code of High Pressure sensor : E505 (The resulting report "Undetermined")
Error code of Low Pressure sensor : E506 (The resulting report "Undetermined")
Determine the status of the High/Low Pressure sensor of the each Outdoor Unit installed before the compressor start.
If the judgment of Outdoor Unit High/Low Pressure sensor is "Undetermined" : Checking in accordance with the following order.
Vacuum mode (All of the Outdoor Unit)
Check the Pressure sensor breakdown
Is Service Valve open state
of installed module? (Each Outdoor Unit )
Is Pressure sensor connector properly connect?
Is voltage 5V between 3, 4 pin
of PCB Pressure sensor terminal?
Is deviation of outdoor
unit as following?"High pressure Max
/Min deviation : less than 2"
Off the vacuum mode
(All of the Outdoor Unit)
[Caution]
- If the judgment of Pressure sensor "Undetermined" :
Display the error to all of the Outdoor Unit and then Auto Trial Operation is exited. (Stop the overall system)
9-6
※ Check the Pressure sensor breakdown after the saturation pressure
of the outdoor temperature or connect the manifold gauge to check the pressure.
Yes
Yes
Yes
Yes
Complete
No
Service Valve opening of the Outdoor Unit
No
No
No
Confirmation and Measures
Replace PCB
Replace Pressure sensor
Samsung Electronics