Tosot TW09HQ3D6D Service Manual page 55

6. Communication malfunction (E6)
Main detection points:
● Check if the connection wire and the built-in wiring of indoor and outdoor unit are connected well and without damage;
● If the communication circuit of indoor mainboard is damaged? If the communication circuit of outdoor mainboard (AP1) is damaged?
Malfunction diagnosis process:
Replace the
wire
Is the malfunction
eliminated?
Yes
52
Yes
Check built-in wiring
of indoor and outdoor
unit
If the wiring is
Yes
damaged?
No
Check the malfunction
No
type with communication
malfunction detector
Malfunction of outdoor
communication circuit
No
Replace indoor
mainboard AP2
E6
If the unit operates normally
before malfunction
Yes
Replace outdoor
Yes
mainboard AP1
Is the malfunction
No
eliminated?
Yes
End
No
Check the connection
wire according to the
wiring diagram.
If the connection wire
is connected well?
No
No
Reconnect the wire or
replace the connection
wire according to the
wiring diagram.
Is the malfunction
eliminated?
Yes
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