Haier AB12CS1ERA Service Manual page 411

Super Match
Failure 11: Low pressure switch failure
Reason: 1. Too low system pressure causes that the unit stops and the compressor protection works, the failure can
be resumed.
2. Pressure switch wire is not fixed well or in open circuit.
Start
Check if the connector
between pressure
switch and PCB is
fixed badly or damaged
(CN20 on PCB)
Yes
Replace pressure switch
connector, shut off and
be electrified again,
re-check
Check if the 2
straight lugs on
No
the pressure
switch work badly
Yes
Replace pressure
switch connector, shut
off and be electrified
again, re-check
If indoor fan motor
cannot startup normally
No
in heating mode(except
for defrost)
Yes
Check if the
indoor motor has
power input
409
Replace main
No
control board
and check again
Replace indoor
No
motor and check
again