Manifold air pressure: Difference between revisions
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===Transfer function=== |
===Transfer function=== |
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The G31 is most likely a [http://www.freescale.com/files/sensors/doc/data_sheet/MPX4250A.pdf Motorola/Freescale MPX4250A]. |
The G31 is most likely a [http://www.freescale.com/files/sensors/doc/data_sheet/MPX4250A.pdf Motorola/Freescale MPX4250A] or similar to [http://nyet.org/cars/info/Map_Sensor_Technical_Specification.pdf Bosch Motorsport 0 281 002 205 ] |
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MPX4250A: |
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VOUT = VS (P × 0.004 - 0.04) |
VOUT = VS (P × 0.004 - 0.04) |
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± (Pressure Error × Temp. Factor × 0.004 × VS) |
± (Pressure Error × Temp. Factor × 0.004 × VS) |
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VS = 5.1 V ± 0.25 VDC |
VS = 5.1 V ± 0.25 VDC |
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Bosch Motorsport variants |
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[[Image:MPX4250A-transfer-function.png]] |
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*0 281 002 205: 0.2-2.5 bar |
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[http://nyet.org/cars/info/Map_Sensor_Technical_Specification.pdf Bosch Motorsport] |
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*0 281 002 244: 0.5-3.5 bar |
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*0 281 002 316: 0.5-4.0 bar |
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==References== |
==References== |
Revision as of 01:52, 18 January 2011
Charge pressure sender G31
Part number 078 906 051
The charge pressure sender is located upstream of the throttle valve control part.
The Motronic supplies the sender with a voltage of 5 volts and earth. The signal which the sender generates is a pressure-proportional voltage ranging from 0 to 5 volts.
At atmospheric pressure (14.7 psi or 1.01 bar at sea-level), the voltage is approx. 1.88 volts.
The signal is used for charge pressure control.
The Motronic also needs information on charge pressure so that it can take countermeasures if the maximum permissible pressure is exceeded.
The absolute maximum pressure reading is approximately 2.559 bar absolute (22.45 psi). Pressure readings that deviate more than ~500mbar from specified pressure may cause throttle cut.
Substitute function and self-diagnosis
If sender G31 fails, the charge pressure is controlled via the characteristic curve (engine speed-dependent). This will result in a deficiency of engine power.
Transfer function
The G31 is most likely a Motorola/Freescale MPX4250A or similar to Bosch Motorsport 0 281 002 205
MPX4250A:
VOUT = VS (P × 0.004 - 0.04) ± (Pressure Error × Temp. Factor × 0.004 × VS) VS = 5.1 V ± 0.25 VDC
Bosch Motorsport variants
- 0 281 002 205: 0.2-2.5 bar
- 0 281 002 244: 0.5-3.5 bar
- 0 281 002 316: 0.5-4.0 bar
References
- AW discussion on MAP sensor function