Carrier 38MGRBQ18B-3 - DIAGNOSIS AND SOLUTION (CONT); Communication Malfunction Between Indoor and Outdoor Units

38MGRBQ: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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DIAGNOSIS AND SOLUTION (CONT)
Communication malfunction between the indoor and outdoor units diagnosis and solution
Troubleshooting
NOTE: The Pics (images) mentioned in the flowchart are located on the following pages.
Error Code E2 / EL 01
Malfunction decision conditions If the indoor unit does not receive the feedback from outdoor unit during 120 seconds.
Supposed Causes
Wiring Mistake
Faulty indoor or outdoor PCB
Indoor / outdoor units communication error
Start: Power off , then Power on the
A/C by the Breaker. (Reconnect the
power wire). Is it still displaying the
error code?
Yes
No
Change outdoor unit PCB assembly
include wiring
Check wiring on the outdoor and indoor
terminal follow the wiring diagram. Is all
connecting correctly?
Yes
No
Measure Vs, is it moving
alternately between positive value
and negative value? (Vs is the
voltage between S and L2). Refer
PIC 1.
Turn on the indoor unit by
remote. Does the indoor unit display?
Turn off the all indoor units. Is IPM
power LED or operating LED lamp
on Refer to PIC 2.?
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 time
Yes
Yes
Change the Indoor PCB
Power on by remote
controller.
Is it still
displaying the error code
after 3 minutes?
Trouble is solved
No second time
No
Yes
Reconnect the wiring
No
change the IPM
No
Is the reactor connecting
well˛
No Reconnect the wiring
Change Outdoor Main PCB
Yes
No
Is main boardĀ ā
lamp on? Refer PIC 3.