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

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)
Temperature sensor malfunction diagnosis and solution
Troubleshooting
ERROR CODE
E4, EC 53, EC 54, EC 56 OR EC 50
MALFUNCTION DECISION
CONDITIONS
If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED displays a failure.
SUPPOSED CAUSES
PCB faulty
Sensor faulty
Wiring mistake
Check the connections
between the 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
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