Carrier 42QFD048D8S Service Manual page 97

TS05-IDU: Open circuit or short circuit of indoor temperature sensor(T1, T2) diagnosis and
solution
Description: If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED displays the failure code.
Recommended parts to prepare:
• Connection wires
• Sensors
• Indoor main PCB
Troubleshooting and repair:
Note: This picture and the value are only for reference, actual appearance and value may vary.
Check the connection between
temperature sensor and PCB.
Is it properly wired?
YES
Measure the resistance value
of the sensor.
Is it within acceptable
parameters?
YES
Replace the indoor main PCB
 Troubleshooting
NO Ensure proper connections.
NO Replace the sensor.
