Haier AS09/12GS2ERA - 7.3.4 The IPM and outdoor PCB dont communicate or Related Abnormality

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Domestic air conditioner
AS09/12GS2ERA 1U09/12BS1ERA-SM
Servive Diagnosis
Normal resistance
Several k
to several M ( )
Unacceptable resistance Short (0 ) or open
7.3.4 The IPM and outdoor PCB don’t communicate or Related Abnormality

outdoor display LED1 flash 4 times Indoor Display F3 

Method of Communication is detected by checking the IPM module and the outdoor PCB
Malfunction
Detection
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
Malfunction Ƶ The outdoor PCB broken leads to communication fault
Decision
Ƶ The IPM module broken leads to communication fault
Conditions

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Supposed Ƶ The outdoor PCB is broken 
Causes Ƶ The IPM module is broken
Ƶ Communication wiring disconnected
Troubleshooting
* Caution  Be sure to turn off power switch before connect or disconnect connector, or
else parts damage may be occurred.
NO
NO
YES
Are they good?
1) Pull out and reinsert the terminals.
2) Replace connected wire
1) Check whether Terminal CN23 and CN22 on the outdoor
mainboard CN10 and CN11 on IPM module
2) Check whether the connected wire between IPM and outdoor
YES
Replace the outdoor IPM
module with a new one.
Replace the outdoor mainboard with a new one
Electrify the machine again and
turn it on, Check whether the
voltage between 1 and 2 o
f
Terminal CN22is about DC5V,
Check whether the voltage
between2 and 3 of Terminal CN22
is about DC15V,
NO