Carrier 40MAQB09B--3 - Communication Malfunction Diagnosis (E1;E2)

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E1, E2 (Communication malfunction between indoor and outdoor units) error diagnosis and
solution.
Error Code E2
Malfunction decision conditions
Indoor unit does not receive the feedback from outdoor unit during 120 seconds or outdoor
unit does not receive the feedback from any one indoor unit during 180 seconds.
Supposed Causes
S Wiring mistake
S Indoor or outdoor PCB faulty
Troubleshooting
Communicaon malfuncon between indoor and
outdoor units
Start: Power off , then Power on the
A/C by the Breaker. (reconnect the
power wire). Is it sll displaying the
error code?
Yes
No
Change outdoor unit PCB assembly(include
wiring) totally
Check wiring on the outdoor and indoor
terminal follow the wiring diagram. Is all
connecng correctly?
Yes
No
Measure Vs, is it moving
alternately between posive value
and negave value? (Vs is the
voltage between S and L2). Refer
PIC 1
Turn on all indoor unit by remote
controller. Is all indoor unit display
Turn off the all indoor units. Is IPM
power LED or operang
LED lamp
On? Refer PIC2
Yes
A: Is all the wiring between
terminal and Indoor PCB
connect ok?
No
Yes
A
No
Reconnect the wiring
Is indoor units number correct? Check
on the outdoor check point . (2 for dual
zone, 3 for tri zone, 4 for qua zone).
Refer PIC 4.
Yes
No first me
Yes
Yes
Change the Indoor PCB
Power on by remote
controller, I
Is it sll
displaying the error code
aer 3 minutes?
Trouble is solved
No second me
No
Yes
Reconnect the wiring
No
change IPM
No
Is the reactor connecng
well˛
No Reconnect the wiring
Change Outdoor Main PCB
Yes
No
Is main boardĀ ā
lamp on? Refer PIC 3.