![background image](http://html1.mh-extra.com/html/carrier/40mahbq06xa/40mahbq06xa_service-manual_2561959018.webp)
SG-40MAHB-01: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
18
DIAGNOSIS AND SOLUTION (CONT)
Indoor / outdoor unit’s communication diagnosis and solution (E1)
Malfunction Decision Conditions
Indoor unit does not receive feedback from the outdoor unit for 110 seconds and this condition happens four times continuously.
Possible Causes:
• Wiring error
• Indoor or outdoor PCB faulty
Troubleshooting
Measure
Vs
. Is it a positive fluctuation?
(
Vs
represents the voltage
S
and
N
of the
outdoor unit. Red pan-S, Black pan-N)
Power off, then restart the unit 2 minutes later.
Replace the indoor main PCB.
Power on. Is the error resolved?
No
Check the indoor wiring connection.
Yes
Check whether the
reactor is normal.
Yes
No
Check the outdoor wiring connection.
Replace the reactor.
Yes
Replace the outdoor main PCB.
Power on. Is the error resolved?
Replace the indoor main PCB.
No
Replace the outdoor main PCB.
Yes
No
Yes
Yes