Carrier 38MARBQ12AA1 Service Manual page 42

DIAGNOSIS AND SOLUTION (CONT)
Outdoor Temperature Sensor Is an Open Circuit or Short Circuited (T3, T4, TP, T2B, TH) (EC53)
Description: If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED displays the failure code.
Recommended parts to repair:
• Connection wires
• Sensors
• outdoor main PCB
Troubleshooting:
Check the connection between
the temperature sensor and PCB.
Is it properly wired? NO Ensure proper connections?
YES
Measure the sensor's
resistance value.
Is it within
NO Replace the sensor.
acceptable parameters?
YES
Replace the outdoor main PCB.
Fig. 41 —Test
NOTE: For certain model, the outdoor PCB could not be removed separately. In this case, the outdoor electric control box should be
replaced as a whole. For certain models, the outdoor unit uses a combination sensor, T3,T4 and TP are the same sensor. Figure 41 and
the value are for reference only.
42
Specifications subject to change without notice. SG-38MARB-01