York YHKE09XEEAMH-RX Service Manual page 38

9.2.2 Indoor / outdoor unit's communication diagnosis and solution(E1)
Error Code
Malfunction decision
conditions
Supposed causes
Trouble shooting:
Power off, then restart the unit 2 minutes later
Power off, then restart the unit 2 minutes later
Measure Vs. Is the voltage moving
Measure Vs. Is the voltage moving
alternately between -25V to 25V?
alternately between -25V to 25V?
(Vs is the voltage between S and N of
(Vs is the voltage between S and N of
outdoor unit. Red pan-S, Black pan-N)
outdoor unit. Red pan-S, Black pan-N)
Check the outdoor wiring connection
Check the outdoor wiring connection
Replace the outdoor main PCB.
Replace the outdoor main PCB.
Replace the indoor main PCB.
Replace the indoor main PCB.
E1
Indoor unit does not receive the feedback from outdoor unit during
110 seconds and this condition happens four times continuously.
Wiring mistake
●
Indoor or outdoor PCB faulty
●
Yes
Yes
Yes
Power on. Is the error
Power on. Is the error
extinguished?
extinguished?
No
Check the indoor wiring connection
Check the indoor wiring connection
Replace the indoor main PCB.
Replace the indoor main PCB.
Power on. Is the error
Power on. Is the error
extinguished?
extinguished?
Replace the outdoor main PCB.
Replace the outdoor main PCB.
36
No
Yes
No