Carrier 38MGRBQ18B-3 - DIAGNOSIS AND SOLUTION (CONT); Sensor Malfunction Diagnosis

38MGRBQ: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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DIAGNOSIS AND SOLUTION (CONT)
E4/EC 50 (Outdoor temperature sensor (coil sensor T3,ambient sensor T4, Compressor discharge sensor
T5?Aindoor coil outlet pipe sensor T2B) malfunction) diagnosis and solution
F1/F2/F3/F4/F5 (No.A,B,C,D,E Indoor unit coil outlet temp. sensor malfunction) diagnosis and solution
Outdoor room temperature sensor T4 is in open circuit or has short circuited (EC 53)
Compressor discharge temperature sensor T5 is in open circuit or has short circuited (EC 54)
Evaporator coil outlet temperature sensor T2B is in open circuit or has short circuited (EC 56)
Troubleshooting
ERROR CODE
E4/F1/F2/F3/F4/F5/ EC 52/EC 53/EC 54/EC 56/EC 50
MALFUNCTION DECISION
CONDITIONS
If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED will display the failure.
SUPPOSED CAUSES
Wiring mistake
Faulty Sensor
PCB faulty
Check the connections
between temperature
sensor and PCB
. Are
the connections good?
Correct the connections.
No
Yes
Yes
Replace indoor or outdoor PCB.
Replace the sensor
C
heck the resistance value
of the sensor via Appendix
1
and Appendix 2
Is it normal?
No