Lennox MPA036S4M-1P - P4 Fault Code

Lennox Mini-Split Service Manual / Page 188
P4 Fault Code
Basic Description:
High temperature sensed at compressor discharge line.
General Note:
When the compressor discharge temperature(T5) is more than 115°C for 10 seconds,
the compressor will stop and restart till T5 is less than 90°C.