Mitsubishi Electric GUG-01SL-E Handbook page 17

Error code Symptom
P2 Liquid pipe ther-
mistor (TH2)
failure
P6 Freezing protec-
tion
Overheating
protection
Cause
Faulty connection of thermistor
connector CN21 on PCB A of the
Dx-coil unit
A break or short in a lead wire for
thermistor (TH2)
Failure of thermistor (TH2)
Refrigerant circuit defect or the
like is causing the rise or fall of a
sensed temperature of the ther-
mistor to 90°C or higher, or -40°C
or lower respectively.
Failure of PCB A of the Dx-coil
unit.
No air is blown from the Lossnay
unit to the Dx-coil unit.
(Air volume is low).
The air filter or Lossnay core of the
Lossnay unit is clogged.
The supply fan of the Lossnay unit
is not operating.
Connector CN82 on PCB A of the
Dx-coil unit is disconnected.
Connectors on PCB B of the Dx-
coil unit are disconnected.
PCB B of the Dx-coil unit is not
functioning properly.
Outdoor unit is not operating prop-
erly.
Overload operation of the outdoor
unit
Refrigerant piping defect
─ 17 ─
Corrective action
Check the connector connection of CN21
on PCB A.
Check the lead wires for thermistor (TH2).
Measure the resistance of the thermistor
with a tester. If it differs significantly from
the following values, replace the thermistor
(TH2, TH5).
<Reference resistance values>
0°C: 15.0 kΩ, 10°C: 9.6 kΩ
20°C: 6.3 kΩ, 30°C: 4.3 kΩ
Check the refrigerant circuit.
( For details, see the outdoor unit service
handbook.)
If no error is detected after checking the
above items, replace PCB A (IF013).
Check that air is properly blown from the
Lossnay unit to the Dx-coil unit.
Clean the air filter or Lossnay core.
Check that the Lossnay unit is operating
properly. (For details, see the Lossnay
service handbook.)
Check the connector connection of CN82
on PCB A.
Check all the connector connections on
PCB B.
• Check the lighting status of the LEDs on
PCB B.
(LED11: unlit, LED12: lit)
• Check LEDs on the control circuit board
of the Lossnay unit, or for any error code
displayed on the remote controllers in-
cluding PZ-61DR-E.
Check that the outdoor unit is operating
properly. (For details, see the outdoor unit
service handbook.)
Check if the outdoor unit is operating under
overload. (For details, see the outdoor unit
service handbook.)
Make sure that there is no problem in
refrigerant piping. (For details, see the
outdoor unit service handbook.)