Carrier 38MHRCQ12AA3 - Diagnosis and Solution: Sensor Errors; Open Circuit or Short Circuit of Temperature Sensor Diagnosis and Solution (E4;E5;F1;F2;F3)

SG-38MHRC-01 Specifications subject to change without notice. 37
DIAGNOSIS AND SOLUTION (CONT)
Open circuit or short circuit of temperature sensor diagnosis and solution (E4/E5/F1/F2/F3)
Description: If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED displays the failure.
Possible causes:
• Wiring mistake
• Faulty sensor
• Faulty PCB
Troubleshooting
Fig. 41 — Check the connection
Check the connection
between the temperature
sensor and PCB.
Correct the connection.No
Yes
Replace the indoor or outdoor
main PCB.
Measure the resistance
value of the sensor.
Replace the sensor.No
Yes