Carrier 38QUA009DS, Service Manual, Page: 97 / 116

94
For 36K-48K:
Malfunction
conditions
Indoor unit does not receive feedback from outdoor unit for 60
seconds OR outdoor unit does not receive feedback from indoor unit
for 120 seconds.
Possible causes
●
Wiring mistakes
●
Faulty indoor or outdoor PCB
Communication malfunction between indoor
and outdoor units
Communication malfunction between indoor
and outdoor units
E1 displayed
E1 displayed
No
Power off, then restart the unit 2
minutes later. Does a problem still
exist?
Power off, then restart the unit 2
minutes later. Does a problem still
exist?
Adopt shield cable/shield
cable earthing
Adopt shield cable/shield
cable earthing
No
Yes
Yes
Remove interference or
add magnet ring on power
wire
Remove interference or
add magnet ring on power
wire
Yes
Replace the signal wire
Replace the signal wire Yes
Pull out and insert back
Pull out and insert back No
No
Replace the indoor main PCB, is the
error resolved?
Replace the indoor main PCB, is the
error resolved?
Yes
Replace the outdoor Main PCB.
Replace the outdoor Main PCB.
No
Is there any interference such
as too many lamps, power
transformers? Or is the signal
wire too long?
Is there any interference such
as too many lamps, power
transformers? Or is the signal
wire too long?
Is the signal wire a shield cable
and is the shield cable a
earthing?
Is the signal wire a shield cable
and is the shield cable a
earthing?
Is the signal wire is broken?
Is the signal wire is broken?
Are the signal wires properly
inserted on PCB?
Are the signal wires properly
inserted on PCB?