York YHKMXH009BARX-FX, Service Manual, Page: 251 / 269

start
no
yes
no
no
yes
as per the wiring
diagram, check if
connection port
between sensor and
PCB is correct
re-fix the
sensor and
check again
check if the sensor
is in open circuit or
the connection port
to PCB is in good
condition
check if the
sensor resistor
value is correct
replace sensor
and check
again
replace sensor
and check
again
PCB is faulty
and repalce it,
check again
yes
Trouble 9: AC current over current protection or current transducer damaged, or compressor blocked
rotor, compressor great vibration, compressor abnormal startup, state detecting curcuit abnormal or
compressor damaged.
The former twice failure can be resumed automatically, if outdoor board occurs this failure always, and
can not be resumed for a long time, that shows:
1. Power module (SPDU) damaged, please replace the power module, then re-wiring as per the wiring
diagram (70% possibility)
2. Short circuit in power board results in the power module damaged (15
％
possibility)
3. Damaged compressor results in this failure (10
％
possibility)
4. Main control board is faulty, replace it (5
％
possibility)
Trouble 10: High pressure failure
Reasons:
1. Over high system pressure results that the unit stop, and the compressor protection will work. The
failure can be resumed.
2. Pressure switch wire is not fixed well or in open circuit.
start
no
check if the connector
between pressure
switch and PCB is
fixed badly or damaged
no
no
no
yes
yes
yes
check if the 2 straight
lugs on the pressure
switch are in good
condition
if outdoor fan
motor cannot
startup normally
in cooling mode
replace main
control board
and check again
replace pressure switch
connector, shut off and
be electrified again,
re-check
replace pressure
switch connector, shut
off and be electrified
again, re-check
check if the
outdoor motor
has power input
replace outdoor
motor and check
again
Trouble 8: Outdoor unit alarms sensor failure
249