SiAF341904E
Troubleshooting by Error Code
Part 6 Service Diagnosis
221
Note(s)
5.24 Activation of Low Pressure Sensor
Applicable
Models
All outdoor unit models
Error Code
E4
Method of Error
Detection
Make judgment of pressure detected by the low pressure sensor with the outdoor unit main
PCB.
Error Decision
Conditions
When low pressure caused a drop while the compressor is in operation:
Operating pressure: 0.07 MPa
Supposed
Causes
Abnormally drop in low pressure
Defective low pressure sensor
Defective outdoor unit main PCB
The stop valve is not opened
Troubleshooting
1. Make a comparison between voltage measured by the pressure sensor and that read by the
pressure gauge.
(The pressure sensor makes measurement of voltage at its connector block to convert it to
pressure.
CHECK 12
)
YES
NO
NO
YES
Are the
characteristics
of the low pressure
sensor normal?
(
∗
1)
NO
YES
(1)
Mount a pressure gauge on the low pressure
service port.
(2)
Reset the operation using the remote
controller, and then restart the operation.
Is the stop
valve open?
- The low pressure sensor is normal, and pressure detection with the
outdoor unit main PCB is also normal.
- The low pressure has really become low.
Replace the outdoor unit main
PCB (A1P).
Replace the low pressure sensor
(S1NPL).
Open the stop valve.
CHECK 2
CHECK 12
Is the
“low pressure”
checked by the
Service Checker same
as the measurement of
the low pressure
gauge?
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Eliminate factors that cause the low pressure to decrease.
Connect the Service Checker, and then make a comparison between “low
pressure” checked by the Service Checker and the measurement of the low
pressure sensor. (
∗
1)
Service Checker
