Carrier 38MGRQ48E 3 Series - Low Pressure Protection Error (P2)

56 Specifications subject to change without notice. 38MGR-04SM
DIAGNOSIS AND SOLUTION (CONT)
Low pressure protection error (P2)
Troubleshooting
ERROR CODE P2
MALFUNCTION DECISION
CONDITIONS
If the sampling voltage is not 5V, the LED displays the failure.
SUPPOSED CAUSES
• Wiring mistake
• Over load protector faulty
• System block
• Outdoor PCB faulty
Yes
Yes
No
No
No
Yes
No
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No
Yes
Yes
No
No
Low Pressure Protection
Is the wiring between the low
pressure protector and main
control board well connected?
Connect the main board correctly.
Is the low pressure
protector broken?
Check if the outdoor ambient
temperature is too low.
Method: Disconnect the plug.
Measure the resistance of the
low pressure protector.
If the protector is normal,
the value is 0.
Replace the low pressure protector.
Stop the unit.
Check if the high pressure
valve core is opened.
Fully open the
high pressure valve.
Check if the outdoor
fan runs properly in the
cooling mode.
Please refer to the Out of Control
Fan Speed solution.
Identify the cause and
resolve the issue.
Replace the outdoor
main board.
Refrigerant is low.
Add more refrigerant.
Check if the
refrigerant system
is operating as designed.