Mitsubishi Electric PUMY-P112VKM4 Technical & Service Manual page 68

Check code
1501
(U2)
Abnormal points and detection methods
If stop valve is closed during cooling operation.
When both of the following temperature conditions have been satisfied for
20 minutes or more during cooling operation.
1. TH22j−TH21j ] −2°C [−3.6_F]
2. TH23j−TH21j ] −2°C [−3.6_F]
Note:
For indoor unit, the abnormality is detected if an operating unit satisfies the
condition.
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Is the outdoor stop valve
(liquid/gas) fully open?
Disconnect the outdoor LEV wiring to
check the resistance.
Is the resistance detected?
v
OCH673D
Closed valve in cooling mode
Diagnosis
Yes
Yes
Causes and checkpoints
Outdoor liquid/gas valve is closed.
Malfunction of outdoor LEV (LEV1)(blockage)
TH21: Indoor intake temperature thermistor (RT11 or TH1)
TH22: Indoor liquid pipe temperature thermistor (RT13 or TH2)
TH23: Indoor gas pipe temperature thermistor (TH-A to E)
LEV: Linear expansion valve
Open the outdoor stop valve (liquid/gas)
No
fully.
No
Replace the outdoor LEV.
Replace the outdoor multi controller circuit
board.
68
Remedy