Carrier 38MGR Series Service Manual page 43

DIAGNOSIS AND SOLUTION (CONT)
Open or short circuit of outdoor temperature sensor) diagnosis and solution F1/F2/F3/F4/F5 (open or
short circuit of indoor coil temperature sensor) diagnosis and solution (E4)
ERROR CODE
MALFUNCTION DECISION
CONDITIONS
SUPPOSED CAUSES
Troubleshooting
Check the connections
between the temperature
sensor and PCB. Are
the connections good?
Check the resistance value
Appendices 1 and 2.
Replace the sensor.
38MGR-04SM
E4/F1/F2/F3/F4/F5/F6
If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED displays the failure.
• Wiring mistake
• Sensor faulty
• PCB faulty
Yes
of the sensors via
Is it normal?
No
Fig. 51 — Check the Sensor Value
Specifications subject to change without notice.
No Correct the connections.
Yes Replace the indoor or outdoor PCB.
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