Carrier 42QFD048D8S Service Manual page 99

TS05-ODU: Open circuit or short circuit of outdoor temperature sensor(T3, T4, TP, T2B,TH)
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
• Outdoor main PCB
Troubleshooting and repair:
Note: For certain models, outdoor PCB could not be removed separately. In this case, the outdoor electric control
box should be replaced as a whole. For certain models, outdoor unit uses combination sensor, T3,T4 and TP are
the same of sensor. 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 outdoor main PCB
 Troubleshooting
NO Ensure proper connections.
NO Replace the sensor.
