Pressure Sensor Voltage Test

Technical Support Subject Pressure Sensor Voltage Test Document Version Department Revision Details Revised by Tech Engineering Implemented EXT-ALL-008 A Tech Document Release SP 22 Jul 2015 RF 22 Jul 2015 N/A 22 Jul 2015 Page 1 of 5 Knowledge Base: www.kb.vmacair.com Email: tech@vmacair.com Web: www.vmacair.com Technical Support: 1(888)241-2289 Toll Free:1(800)738-8622 Fax: 1(877)740-3201 System or Parts affected 150 PSI Pressure Sensor P/N# 3500288 200 PSI Pressure Sensor P/N# 3501037  Underhood150 (V910xxx)  Underhood70 (V90xxxx)  PREDATAIR40 (H400001)  PREDATAIR60 (H600002)  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. Technical Support Subject Pressure Sensor Voltage Test Document Version Department Revision Details Revised by Tech Engineering Implemented EXT-ALL-008 A Tech Document Release SP 22 Jul 2015 RF 22 Jul 2015 N/A 22 Jul 2015 Page 2 of 5 Knowledge Base: www.kb.vmacair.com Email: tech@vmacair.com Web: www.vmacair.com Technical Support: 1(888)241-2289 Toll Free:1(800)738-8622 Fax: 1(877)740-3201 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: Technical Support Subject Pressure Sensor Voltage Test Document Version Department Revision Details Revised by Tech Engineering Implemented EXT-ALL-008 A Tech Document Release SP 22 Jul 2015 RF 22 Jul 2015 N/A 22 Jul 2015 Page 3 of 5 Knowledge Base: www.kb.vmacair.com Email: tech@vmacair.com Web: www.vmacair.com Technical Support: 1(888)241-2289 Toll Free:1(800)738-8622 Fax: 1(877)740-3201 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 + 0.5 200 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 Technical Support Subject Pressure Sensor Voltage Test Document Version Department Revision Details Revised by Tech Engineering Implemented EXT-ALL-008 A Tech Document Release SP 22 Jul 2015 RF 22 Jul 2015 N/A 22 Jul 2015 Page 4 of 5 Knowledge Base: www.kb.vmacair.com Email: tech@vmacair.com Web: www.vmacair.com Technical Support: 1(888)241-2289 Toll Free:1(800)738-8622 Fax: 1(877)740-3201 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 Technical Support Subject Pressure Sensor Voltage Test Document Version Department Revision Details Revised by Tech Engineering Implemented EXT-ALL-008 A Tech Document Release SP 22 Jul 2015 RF 22 Jul 2015 N/A 22 Jul 2015 Page 5 of 5 Knowledge Base: www.kb.vmacair.com Email: tech@vmacair.com Web: www.vmacair.com Technical Support: 1(888)241-2289 Toll Free:1(800)738-8622 Fax: 1(877)740-3201 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. Figure 6 Voltage Supply 4.5 – 5.5V The Signal Wire (can be white or green) should read between 0.5 – 4.5V (See Chart)