Carrier 38MGRBQ18B-3 - Page 46

38MGRBQ: Service Manual
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46
DIAGNOSIS AND SOLUTION (CONT)
E2/ EL 01 (Communication malfunction between indoor and outdoor units) diagnosis and solution
Troubleshooting
ERROR CODE
E2/ EL 01
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
Wiring mistake
Faulty indoor or outdoor PCB
Communication malfunction between indoor and
outdoor units
Yes
No
Change outdoor unit PCB assembly
(include wiring)
Check wiring on the outdoor and indoor
terminal using the wiring diagram.
Is it connected correctly?
Yes
No
Measure Vs, is it moving
alternately between positive value
and negative value? (Vs is the
voltage between S and L2). Refer
to PIC 1
Turn on the indoor unit by remote
controller. Does the indoor unit
power on?
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 the indoor PCB
well connected?
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 fir
st time
Yes
Yes
Change the Indoor PCB
Power on by remote
controller, I
s it still
displaying the error code
after 3 minutes?
Problem solved
No second time
No
Yes
Reconnect the wiring
No
change IPM
No
Is the reactor connected
No Reconnect the wiring
Change the outdoor Main PCB
Yes
No
Is main boardĀ ā
lamp on? Refer PIC 3.
Start: power off, then use the
breaker to power on the unit.
Reconnect the power wire.
Does the error code still appear?