Download EXT-ALL-008 Pressure Sensor Voltage Test

Technical Support
Subject
Pressure Sensor Voltage Test
System or Parts affected
150 PSI Pressure Sensor P/N# 3500288
 Underhood150 (V910xxx)
 Underhood70 (V90xxxx)
 PREDATAIR40 (H400001)
 PREDATAIR60 (H600002)
200 PSI Pressure Sensor P/N# 3501037
 Underhood “G” (V90Gxxx)
 RAPTAIR / MF (D60000x)
Index
System or Parts affected ............................................................. 1
Overview ....................................................................................... 1
Check Pressure Sensor Plug Pins: ........................................... 1
Test Method .................................................................................. 2
Pressure Sensor Identification: ................................................. 2
Pressure Sensor Voltage Charts: ............................................. 3
How to Back Probe the pressure sensor: ................................. 4
Overview
VMAC’s pressure sensor is an electromechanical device that translates air pressure into voltage. The
pressure sensor’s voltage output varies depending on how much pressure is applied to its diaphragm.
Voltage increases as pressure increases.
Check Pressure Sensor Plug Pins:
1) Confirm the pins are seated and in the proper location.
2) The Red wire supplies power to the sensor, this should have 4.5-5.5V with the system
turned on.
3) The Black wire is the ground.
4) The Green or White wire is the signal wire; this is what the sensor uses to send information.
(Figure 1)
Figure 1
Ensure the pins are seated correctly and that there is no corrosion or damage to the
connector pins.
Document
EXT-ALL-008
Version
A
Department
Tech
Revision Details
Document Release
Knowledge Base: www.kb.vmacair.com
Email: [email protected]
Web: www.vmacair.com
Technical Support: 1(888)241-2289
Toll Free:1(800)738-8622 Fax: 1(877)740-3202
Revised by
SP 22 Jul 2015
Tech
RF 22 Jul 2015
Engineering
N/A
Implemented
22 Jul 2015
Page 1 of 5
Technical Support
Subject
Pressure Sensor Voltage Test
Test Method
1) Ensure that the system is depressurized (0 PSI).
2) Install a 200 PSI mechanical pressure gauge on the compressor, ideally install a T fitting before the
pressure sensor and tie in the pressure gauge here. (Figure 2)
Figure 2
3) With the engine off, key in the run position and park brake applied, Measure voltage on the RED
pressure sensor wire (this should be 4.5 – 5.5V). If there is no voltage then you should check the red
wire at the throttle control. If there is no voltage here the throttle control is faulty and must be
replaced.
4) With the engine off, key in the run position, turn on the VMAC Compressor what voltage is
on the Signal wire?
5) With the engine on and compressor running what is the voltage on the Signal wire? Do the
readings match the pressure to voltage charts on page 3 or 4?
Pressure Sensor Identification:
Document
EXT-ALL-008
Version
A
Department
Tech
Revision Details
Document Release
Knowledge Base: www.kb.vmacair.com
Email: [email protected]
Web: www.vmacair.com
Technical Support: 1(888)241-2289
Toll Free:1(800)738-8622 Fax: 1(877)740-3202
Revised by
SP 22 Jul 2015
Tech
RF 22 Jul 2015
Engineering
N/A
Implemented
22 Jul 2015
Page 2 of 5
Technical Support
Subject
Pressure Sensor Voltage Test
Pressure Sensor Voltage Charts:
With the compressor on, measure the voltage on the Signal wire, the voltage reading should correspond
with the system air pressure.
150 PSI Pressure Sensor P/N# 3500288
 Underhood70 / 150 (V900xxx / V910xxx)
 PREDATAIR (H400001 / H600002)
Pressure (PSI)
Voltage
0
0.5
10
0.74
20
1.01
30
1.28
40
1.55
50
1.82
60
2.09
70
2.36
80
2.63
90
2.90
100
3.17
105
3.30
110
3.43
115
3.57
120
3.70
125
3.83
130
3.97
135
4.10
140
4.23
145
4.37
150
4.50
Formula: Voltage = Pressure X .027 + 0.5
Document
EXT-ALL-008
Version
A
Department
Tech
Revision Details
Document Release
Knowledge Base: www.kb.vmacair.com
Email: [email protected]
Web: www.vmacair.com
Technical Support: 1(888)241-2289
Toll Free:1(800)738-8622 Fax: 1(877)740-3202
200 PSI Pressure Sensor P/N# 3501037
 Underhood “G” (V90Gxxx)
 RAPTAIR / MF (D60000x)
Pressure (PSI)
Voltage
0
0.5
10
0.70
20
0.90
30
1.10
40
1.30
50
1.50
60
1.70
70
1.90
80
2.10
90
2.30
100
2.50
105
2.60
110
2.70
115
2.80
120
2.90
125
3.00
130
3.10
135
3.20
140
3.30
145
3.40
150
3.50
155
3.60
160
3.70
165
3.80
170
3.90
175
4.00
180
4.10
185
4.20
190
4.30
195
4.40
200
4.50
Formula: Voltage = Pressure X .02 + 0.5
Revised by
SP 22 Jul 2015
Tech
RF 22 Jul 2015
Engineering
N/A
Implemented
22 Jul 2015
Page 3 of 5
Technical Support
Subject
Pressure Sensor Voltage Test
How to Back Probe the pressure sensor:
The pressure sensor must be connected for testing.
1) Locate rear of 3 wire pressure sensor connector. (Figure 2)
Figure 3
2) Use flat blade screw drive to gently pry the seal out of place, taking care not to damage the seal
or terminals. (Figure 4)
Figure 4
Document
EXT-ALL-008
Version
A
Department
Tech
Revision Details
Document Release
Knowledge Base: www.kb.vmacair.com
Email: [email protected]
Web: www.vmacair.com
Technical Support: 1(888)241-2289
Toll Free:1(800)738-8622 Fax: 1(877)740-3202
Revised by
SP 22 Jul 2015
Tech
RF 22 Jul 2015
Engineering
N/A
Implemented
22 Jul 2015
Page 4 of 5
Technical Support
Subject
Pressure Sensor Voltage Test
3) Pull the seal out of the rear of the connector. (Figure 5)
Figure 5
4) You will be able to see the wire terminals, use a volt meter to measure at the points shown. Use
the positive lead from the volt meter at these points and have the negative lead from the volt
meter to the system battery negative post.
Voltage Supply 4.5 – 5.5V
The Signal Wire (can
be white or green)
should read between
0.5 – 4.5V (See Chart)
Figure 6
Document
EXT-ALL-008
Version
A
Department
Tech
Revision Details
Document Release
Knowledge Base: www.kb.vmacair.com
Email: [email protected]
Web: www.vmacair.com
Technical Support: 1(888)241-2289
Toll Free:1(800)738-8622 Fax: 1(877)740-3202
Revised by
SP 22 Jul 2015
Tech
RF 22 Jul 2015
Engineering
N/A
Implemented
22 Jul 2015
Page 5 of 5