Troubleshooting - Trane Hyperion AM8A0A24V21CA Series Field Reference Data

Troubleshooting

Verify connections for sensors are
plugged in and connected properly
Start Here
Turn System switch on thermostat to
OFF and Fan to ON position
Does voltage(s) measured correspond
to return air temperature? +-3F
J3
Wait 10 minutes
NO
Remove J3 connector
measured between pins
4
5
6
7
Remove J3 connector and
measure resistance across
Do resistance readings
match chart (within +- 5%)
Measure resistance of each
sensor lead to ground
Sensors are good NO
Sensor Check
Measure return air temperature
YES
Is 4.5 – 5 VDC
NO
4-5 and pins 6-7?
YES
BK-BK and OR-OR
NO
for the return air
temperature?
Are zero ohms
measured from
YES
any lead to
ground
TAM8­32
Measure VDC at J3 connector on EVC.
(See EVC table for J3 location)
Proceed to next
Replace EVC
Replace sensor(s)
Check sensor leads for
short to ground. Replace
or repair as needed
step