U3-07 - Transmission Abnormality On Test Run; U3-08 - Transmission Abnormality On Test Run; U4-01 - Communication Error On; Transmission Line - Daikin VRV IV+ Service Manual

2 Troubleshooting
Possible cause: Faulty or interruption in transmission line
between indoor units and outdoor unit.
2 Check the F1‑F2 transmission line between the indoor units and
outdoor unit. See "4.1 Electrical circuit" on
Possible cause: Faulty or interruption in transmission line
between indoor units and outdoor unit.
3 Perform a test run from the outdoor unit. See installer reference
guide for more information.
INFORMATION
If all procedures listed above have been performed and the
problem is still present, contact the helpdesk.
2.3.125 U3-07 – Transmission abnormality on test
run
Trigger Effect
Test run could NOT Unit will NOT
start or abort due to operate.
transmission issues.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed
order.
1 Check if communication between outdoor unit and indoor units
is initialised. Check field setting 1‑10 for count of indoor units,
see "6.9 Field settings" on
than expected, communication between 1 or more indoor unit(s)
and outdoor unit is NOT correct. Check the F1‑F2 transmission
line between the indoor unit and outdoor unit, see
circuit" on page 130.
Possible cause: Faulty or interruption in transmission line
between indoor units and outdoor unit.
2 Check the F1‑F2 transmission line between the indoor units and
outdoor unit. See "4.1 Electrical circuit" on
Possible cause: Faulty or interruption in transmission line
between indoor units and outdoor unit.
3 Perform a test run from the outdoor unit. See installer reference
guide for more information.
INFORMATION
If all procedures listed above have been performed and the
problem is still present, contact the helpdesk.
2.3.126 U3-08 – Transmission abnormality on test
run
Trigger Effect
Test run could NOT Unit will NOT
start or abort due to operate.
transmission issues.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed
order.
1 Check if communication between outdoor unit and indoor units
is initialised. Check field setting 1‑10 for count of indoor units,
see "6.9 Field settings" on
than expected, communication between 1 or more indoor unit(s)
and outdoor unit is NOT correct. Check the F1‑F2 transmission
line between the indoor unit and outdoor unit, see
circuit" on page 130.
Service manual
58
https://daikin-p.ru/catalog/vrv-daikn/naruzhnye-vrv-bloki-daikin
page 130.
Reset
Restart test run.
page 188. If less indoor units shown
"4.1 Electrical
page 130.
Reset
Restart test run.
page 188. If less indoor units shown
"4.1 Electrical
Possible cause: Faulty or interruption in transmission line
between indoor units and outdoor unit.
2 Check the F1‑F2 transmission line between the indoor units and
outdoor unit. See "4.1 Electrical circuit" on
Possible cause: Faulty or interruption in transmission line
between indoor units and outdoor unit.
3 Perform a test run from the outdoor unit. See installer reference
guide for more information.
INFORMATION
If all procedures listed above have been performed and the
problem is still present, contact the helpdesk.
2.3.127 U4-01 – Communication error on Q1-Q2

transmission line

Trigger Effect
Main PCB detects Unit will stop
abnormal operating.
transmission on Q1-
Q2 transmission line
between multi
outdoor units.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed
order.
1 Check the Q1‑Q2 communication between the outdoor units.
See "4.1 Electrical circuit" on
Possible cause: Faulty or interruption in communication
between outdoor units.
2 Perform a check of the main PCB. See
page 106.
Possible cause: Faulty main PCB.
3 Perform a power reset. If the error disappears and is raised
again after a while, check for the presence of an external
source causing electrical noise. See
page 138.
Possible cause: External source may cause interference.
INFORMATION
If all procedures listed above have been performed and the
problem is still present, contact the helpdesk.
2.3.128 U4-03 – Communication error on F1-F2
transmission line
Trigger Effect
Main PCB detects Unit will stop
abnormal operating.
transmission on F1-
F2 transmission line
to indoor units.
Transmission
between indoor units
and outdoor unit is
interrupted while in
initialization.
page 130.
Reset
Auto reset.
page 130.
"3.9 Main PCB" on
"4.3 External factors" on
Reset
Auto reset.
RYYQ+RYMQ+RXYQ8~20U7Y1B
VRV IV+ Heat Pump
ESIE18-14 – 2019.07