Carrier 42QFD048D8S Service Manual page 98

TS05-L-ODU: Open circuit or short circuit of outdoor temperature sensor(T3, T4, TP, T2B) or
outdoor unit EEPROM parameter error diagnosis and solution
Description: If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED displays the failure code or
Outdoor PCB main chip does not receive feedback from EEPROM chip or compressor driven chip.
Recommended parts to prepare:
• Connection wires
• Sensors
• Outdoor main PCB
Troubleshooting and repair:
Remarks:
EEPROM: A read-only memory whose contents can be erased and reprogrammed using a pulsed voltage.
The location of the EEPROM chip on the outdoor PCB is shown in the following image:
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.
