Pioneer LISAS-B-1403 Service Manual page 141

2.4.4.13. P4 malfunction
When compressor discharge temperature is higher than 115°C, the unit will stop, and unit runs again when
compressor discharge temperature is lower than 90°C.
P4 display
Temperature protection of
compressor discharge
Check whether the
compressor discharge temp.
is more than 115°C ?
No
Check whether the wiring
connection is right between
compressor discharge temp.
sensor and PCB according
to wiring diagrams?
Yes
Judge: The
discharge temp.
sensor is broken
Method: Check whether the
resistance of compressor
discharge temp. sensor is
right refer to the Appendix 2
Yes
Replace outdoor main board
Electrical Control System
Check whether the
Yes
refrigerant is leak
No Correct the wiring connection
No Replace the compressor discharge temp. sensor
Yes Stop leaking and add refrigerant
Trouble is solved
Troubleshooting
139