Trane 4TXM2318BF300AA Service Manual page 145

[42,43] High Or Low Pressure Switch Shut Off Failure
Check if the pressure switch
close,measure if terminal is
conductive by multimeter
Check if stop valve is open
Check if the PMV coil is ok
Make pressure switch terminal on
PCB in short circuit, check if failure
Replace pressure switch
connection is ok
Y
If the system pressure
match the condition
that pressure switch
shut off
Y
Make pressure switch
Y
Check if the system is
clogged
N
If the system is lack of
refrigerant
N
Y
Y
still exists
N
and measure again
N
Reconnect
N
Replace pressure switch
N
Y
Check the piping system
Y
Charge refrigerant
N
Check the piping system
N
Reconnet
Y
Replace PCB
143