Toshiba MMU-P0121H Service Manual page 83

Check code
[A7]
TS condition gas leak detection
In cooling
*
only model
In there blockage in
the check valve to interrupt
the liquid line?
NO
Replace the check valve
Check code
[AA]
Pd sensor alarm
It is abnormal output voltage of Pd sensor. Check disconnection of connector connection circuit (Pd sensor :
CN501) and output voltage of the sensor.
If the sensor is normal, replace the outdoor interface P.C. board.
1. Outdoor unit service valve closed
2. Blockage of check valve to interrupt the liquid line.
3. Outdoor PMV A error
4. TS sensor error
5. Insufficient refrigerant, blockage in pipe
6. 4-way valve error
Are gas pipe,liquid pipe,
YES
and service valve of the
outdoor unit fully open?
YES
Is outdoor PMV A normal?
1. Connector connection
2. Wiring
3. Coil
4. Valve unit
5. Outdoor P.C. board
YES
YES
Is resistance characteristics
of TS sensor normal?
YES
Is refrigerant bypassed from
discharge port to compressor
suction port with 4-way valve?
YES
Insufficient refrigerant,
blockage, pipe breakage
Pd sensor output voltage alarm
Operation cause
NO
NO
NO
NO
Check and replace 4-way valve unit.
Check there is no blockage or pipe
(
breakage, and then addrefrigerant according
to judgment of refrigerant amount.
Operation cause
3-80
Open service valve fully.
Repair outdoor PMVA.
Replace TS sensor.
)