Signal Transmission Error On Outdoor Unit Pcb - Daikin RXL-W Series Service Manual

Troubleshooting for Outdoor Unit

7.18 Signal Transmission Error on Outdoor Unit PCB

U7
Error Code
Method of Error Communication error between microcomputer mounted on the main PCB and PM1.
Detection
Error Decision
 The abnormality is determined when the data sent from the PM1 cannot be received for 9
Conditions
 The error counter is reset when the data from the PM1 can be successfully received.
Supposed
 Defective outdoor unit PCB
Causes
Troubleshooting
185
seconds.
Be sure to turn off the power switch before connecting or disconnecting
Caution
connectors, or parts may be damaged.
Turn off the power. Then, turn on
the power to restart the system.
Error again?
YES
NO
SiUS092231E
The cause can be an
external factor other than
the malfunction.
Observe the operating
condition in long term.
Replace the outdoor unit
PCB (main PCB).
(R21808)
Part 6 Service Diagnosis