Service Manual

─ 35 ─
Error
Code
LED1
(green)
LED2
(red)
Symptom Cause Corrective action
5102 5
blinks
Return air
(RA) thermis-
tor related
error
Faulty connection of the thermistor
connector (CN5) on the control cir-
cuit board
Check the connector (CN5)
connection.
Thermistor failure Disconnect the connector (CN5),
and check the resistance of the
thermistor.
If the equivalent thermistor resis-
tance differs greatly from the
ambient temperatures, replace the
thermistor. (See (5) Temperatures
and thermistor resistance table
(page 39).)
5501 12
blinks
CO2 sensor
error (Optional
components:
PZ-70CSW-E,
PZ-70CSB-E)
The connectors for the CO2 sensor
are disconnected.
Check the connector connections
(CN34 (only for PZ-70CSW-E),
CN23, CN26, and CN35) on the
control circuit board.
CO2 sensor failure Check the CO2 sensor wiring
according to the PZ-70CSW-E/
PZ-70CSB-E Installation and
Instruction Manual. If the problem
persists even after correcting the
wiring, replace the CO2 sensor.
Even though the CO
2 sensor is not
connected, CO2 sensor setting (the
function selection switches (SW5-6
to SW5-8) on the circuit board or
the function setting (No. 66) of
PZ-62DR-EA) is set as shown below.
• “PZ-70CSW-E connected” (SW5-6: ON,
SW5-7 and SW5-8: OFF, or No.66: 5)
• “PZ-70CSB-E connected” (SW5-6 and
SW5-7: ON, SW5-8: OFF, or No.66: 7)
When the CO2 sensor is not con-
nected, set the function selection
switches (SW5-6 to SW5-8) on the
circuit board to OFF, or the function
setting (No. 66) of PZ-62DR-EA to
“1: No external fan speed control
input”.
6201
PZ-62DR-EA
circuit board
failure
Remote controller failure Replace the PZ-62DR-EA remote
controller.
6202
PZ-62DR-EA
circuit board
failure
Clock function of the remote control-
ler is not working properly.
Replace the PZ-62DR-EA remote
controller.
6600
6
blinks
Multiple
address error
The system contains two or more
units (*3) with the same address in
the same M-NET transmission cable
line.
Find the units (*3) with the same
address, and set unique addresses
to these units.
(*3) This refers to devices assigned an address number in MELANS such as the Lossnay unit, City Multi indoor
unit, City Multi outdoor unit, or system controller.