Trane 4TVH0086FE000AA Service Manual page 126

Procedure
Compressor top temperature sensor
and/or discharge pipe temperature
sensor connections on main PCB are
Compressor top temperature sensor
and/or discharge pipe temperature
sensor have short circuited or failed
Poor heat insulation of compressor top
temperature sensor resulting in
temperature reading lower than actual
Discharge pressure is too high
Replace outdoor main PCB
Notes:
1. Compressor top temperature sensor and discharge pipe temperature sensor connections are ports CN4 and CN5 on the main PCB (labeled 3 and 4,
respectively, in Figure 5-2.1 in Part 5, 2.1 "Ports").
2. Measure sensor resistance. If the resistance is too low, the sensor has short-circuited. If the resistance is not consistent with the sensor's resistance
characteristics table, the sensor has failed. Refer to Table 6-3.2 in Part 6, 3.1 "Temperature Sensor Resistance Characteristics".
3. Excess refrigerant causes discharge temperature to be lower than normal, discharge pressure to be higher than normal and suction pressure to be higher
than normal. For normal system parameters refer to Table 6-3.4 and 6-3.5 in Part 6, 3.2 "Normal Operating Parameters of Refrigerant System".
4. See "P1 Troubleshooting".
PP
loose 1
No
No
temperature
No
Excess refrigerant
3
No
No
Ensure the sensors are connected
Yes
Yes
2
Ensure sufficient heat insulation for
Yes
compressor top temperature senor
Discharge part of the refrigerant. Add oil
Yes
Yes
Troubleshoot as for a P1 error
125
properly
Replace the faulty sensor(s)
if it leaks during discharge
4