Haier AB12CS1ERA Service Manual page 400

4-way valve reversing failure
If connection between 4-way
valve and PCB is good
Y
If coil of 4-way valve
fixed well and if its
characteristic is
correct
Y
If system meets
condition of 4-way
valve reversing: Pd-
Ps>0.6Mpa
Y
Measure if CN5 voltage
on PCB is 208/230VAC
after 4-way valve reversing
conditon is met
Y
If there is air noise after 4-way
valve reverses, and if the
temp. of connection pipes
with 4-way valve is
normal
N
Reconnect
N
Fix again or replace the sensor
Y
Check if compressor is operation
N
Replace PCB
N
Replace 4-way valve
398
Super Match