16 May 75
Symptom: DXF-19, DXH-19, MGC-19 – ERROR CODE P4
Solution: MULTIPLE SOLUTIONS
Cause: INVERTER COMPRESSOR DRIVE ERROR
Remarks:
DESCRIPTION:
AN ABNORMAL INVERTER COMPRESSOR DRIVE IS DETECTED BY A SPECIAL DETECTION CIRCUIT, INCLUDING COMMUNICATION SIGNAL DETECTION, VOLTAGE DETECTION, COMPRESSOR ROTATION SPEED SIGNAL DETECTION, ETC.
***REPAIR OPTION 1 (FOR 9K – 24K):***
1) CHECK THE WIRING BETWEEN THE PCB AND COMPRESSOR:
IS IT WIRED IMPROPERLY?
YES = ENSURE PROPER CONNECTIONS OR REPLACE THE WIRES AND CONNECTORS
NO = CHECK 2)
2) CHECK THE IPM:
IS IT FUNCTIONING PROPERLY?
NO = REPLACE THE IPM BOARD OR REPLACE THE OUTDOOR PCB
YES = CHECK 3)
3) CHECK THE OUTDOOR FAN AND THE OUTDOOR UNIT VENTILATION:
IS IT FUNCTIONING PROPERLY?
NO = CHECK THE SOLUTION FOR THE FAN SPEED MALFUNCTION (ERROR CODE E3)
YES = CHECK 4)
4) CHECK THE COMPRESSOR RESISTANCE VALUES:
ARE THEY WITHIN ACCEPTABLE PARAMETERS?
NO = REPLACE THE COMPRESSOR
YES = REPLACE THE OUTDOOR PCB
***REPAIR OPTION 2 (FOR 30K-36K):***
PLEASE CHECK PAGE 110 OF ATTACHMENT FOR DETAILED SERVICE DIAGRAM.
NO = CHECK 2)
YES = CHECK 3)
YES = CHECK 4)
YES = REPLACE THE OUTDOOR PCB