[42] Open high pressure switch
High pressure switch: Switch circuit has been detected open for
30 seconds (after 3 minute of compressor run time). Error locks
if it occurs 3 times in 1 hour.
Possible causes:
• Incorrect pressure switch wiring
• Abnormal system pressure
• System is clogged
• Incorrect refrigerant charge
• Bad valve
• Pressure switch is bad
• PCB is bad
[43] Open low pressure switch
Low pressure switch: Switch has been detected open
for 60 seconds (after 3 minute of compressor run
time) or open for 30 seconds during standby.
Possible causes:
• Incorrect pressure switch wiring
• Abnormal system pressure
• System is clogged
• Incorrect refrigerant charge
• Bad valve
• Pressure switch is bad
• PCB is bad
I-26
Flow Charts
Topic Title
switch terminal on the PCB.
Does the system report a
Is the resistance of Te and
Power off. Is pressure switch
wiring connection ok?
Use multimeter to check the high
pressure switch. Is the switch
short circuited?
Is the EEV coil wiring correct and
firmly in place?
Is the stop valve is open?
Is the piping system clogged?
Is the connection pipe bent?
Use a multimeter to check
the resistance of Tc & Tm.
Are they withing range?
TROUBLESHOOTING & REFERENCES
Power on
Short the high pressure
failure?
No
Is the fan motor is ok?
Yes
No
Tc within range?
No
Yes
No
Yes
No
Yes
No
No
Yes
No
No
Yes
No
Yes
The PCB is bad,
replace it.
No
Replace the fan
motor
Replace
sensor
Reconnect
The pressure is bad,
replace it.
Reconnect the EEV
coil wiring
Open the stop valve
Clean the piping system
Replace the connection
pipe
Replace the
sensor