Daikin FTX25JVEA9, Service Manual

Page: 306 / 410

Si18-201 Troubleshooting - Outdoor Unit Related
Service Diagnosis 293
3.3.29 Transmission Error between Indoor Unit and BP Unit
Outdoor Unit
Indication
U6
Method of
Malfunction
Detection Transmission error is detected when BP unit could not correctly receive the data from BP unit to
transmit the data incorrectly to outdoor unit.
Malfunction
Decision
Conditions When BP unit could not correctly receive the data from indoor unit continuously for 15 seconds
and transmitted the data incorrectly to outdoor unit.
Supposed
Causes
"
Incorrect connection of transmission wire
"
Distortion of power supply waveform
Troubleshooting
Check No.14
Refer to P.308
Start
YES
Check transmission wire.
Could be outside causes
other than errors.
Probe where the noise
comes from and apply
remedy required.
Probe causes to deform the
power supply waveform
and apply remedy required.
If indoor unit is probed to
be normal by the diagnosis,
replace BP unit PC board.
Is it normal?
(MF049)
NO
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
Check transmission wire
between indoor unit - BP unit.
Is Seg.7 of U6
displayed?
NO
Turn the power supply on
again.
YES
Check No. 14
Check power supply
waveform.
Is it deformed?
NO
YES