Carrier DHMSHAQ09XA1 Service Manual page 24

DIAGNOSIS AND SOLUTION (CONT)
Refrigerant Leakage Detection diagnosis and solution (EC)
Error Code
Malfunction decision conditions
Supposed causes
Troubleshooting
Power off, then restart the
Check cool air blowing out
from indoor air outlet
Check for system blocking and
clear the block
EC
Define the evaporator coil temp.T2 of the compressor. It starts running in Tcool.
At first, 5 minutes after the compressor starts up, if T2 ＜Tcool－35.6
run for 4 seconds and this situation occurs 3 times, the display area displays"EC"and the air
conditioner will turn off.
·T2 sensor faulty
·Indoor PCB faulty
·System problems, such as leakage or blocking.
unit 2 minutes later.
Yes
No
Check for system leaks
No
Yes Check the T2 sensor
Replace indoor PCB.
Yes
Repair the leakage and
recharge the refrigerant.
24
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F (Tcool－2 C) does not
Yes