Daikin Aurora Series, Service Manual, Page: 310 / 333

Check SiUS341802E
297 Service Diagnosis
3.9 Pressure Sensor Check
Voltage Measurement Point of the High Pressure Sensor
Voltage Measurement Point of the Low Pressure Sensor
CHECK 12
High Pressure (P
H
)
Low Pressure (P
L
)
Output Voltage V
H
, V
L
Detected Pressure
40.8
35.7
30.6
25.5
20.4
15.3
10.2
5.1
–5.1 –72.5
0
45.9
51.0 5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
–0.5
–0.5 0 0.5 1 1.5 2 2.5 3 3.5 4
(VDC)
(kg/cm
2
) (psi) (MPa)
P
H
, P
L
P
H
(MPa) = × V
H
– × 0.5
P
L
(MPa) = × V
L
– × 0.5
P
H
: High pressure (MPa)
P
L
: Low pressure (MPa)
V
H
: Output Voltage (High Side) (VDC)
V
L
: Output Voltage (Low Side) (VDC)
4.15
3.0
4.15
3.0
1.7
3.0 1.7
3.0
1 MPa = 145 psi
725
653
580
508
435
363
290
218
145
72.5
0
+5 V
(4)
(3)
(2)
(1)
Red
Black
White
Connector for high
pressure sensor (Red)
High
pressure
sensor
Microcomputer
A/D input
Make measurement of DC
voltage between these wires.
+5 V
(4)
(3)
(2)
(1)
Connector for low pressure sensor
Microcomputer
A/D input
Make measurement of DC voltage between these wires.
(Blue)
Red
Black
White
Low
pressure
sensor