Bosch Maf - Voltages range from ? 0.0 to 5.00 V. What is the resolution between these two points.
05-12-2004, 07:45 PM
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Bosch Maf - Voltages range from ? 0.0 to 5.00 V. What is the resolution between these two points.
Sorry i dont have a car yet, but - if i can get my hands on e Shop vac a MM and a Mas i wont have to ask you guys.
Im assuming those values are the only ones used by the ECU? does the actual Maf unit do the correct conversion for TEMP intital, or is that prosseed by the ECU.
Im assuming those values are the only ones used by the ECU? does the actual Maf unit do the correct conversion for TEMP intital, or is that prosseed by the ECU.
05-13-2004, 06:15 AM
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(g/s) would be a function of the Cross sectional area of the housing.
the voltage resolution would be, the incrimental steps between differnt values.
like, is the maf reliable in gernerating .001 V incriments? does the ECU have a analog digital converter whats its resolution? , but I have to consider it if i where make a digitizal MAF signal.
like, is the maf reliable in gernerating .001 V incriments? does the ECU have a analog digital converter whats its resolution? , but I have to consider it if i where make a digitizal MAF signal.
05-13-2004, 07:00 AM
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Here's the transfer function....
<img src="http://pictureposter.audiworld.com/12130/transfer2.jpg">
Taken from the MAF transfer function in the nonDBW ECU.
There's a catch though. This is the voltage as seen by the processor, and there is about a 7% voltage drop from the sensor voltage to what the processor sees. So the actual max usable sensor voltage is about 5.35V or so. The meter will go above that, but the ECU can't use it.
Taken from the MAF transfer function in the nonDBW ECU.
There's a catch though. This is the voltage as seen by the processor, and there is about a 7% voltage drop from the sensor voltage to what the processor sees. So the actual max usable sensor voltage is about 5.35V or so. The meter will go above that, but the ECU can't use it.
05-13-2004, 08:08 AM
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The processor is capable of 10-bit A/D conversion....
but only does an 8-bit conversion on the MAF and other sensors (except O2 sensor, it does 10-bit on that)
So, roughly 0.02V resolution, and the MAF resolution in the ECU is 0.25kg/hr (0.07 g/s)
What exactly are you trying to do? Run a MAP instead of a MAF?
So, roughly 0.02V resolution, and the MAF resolution in the ECU is 0.25kg/hr (0.07 g/s)
What exactly are you trying to do? Run a MAP instead of a MAF?
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05-13-2004, 09:26 AM
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so basically thats the calibration curve that would need the change if the maf changed.
im assuming you created the graph directly from the transer function and not empirically generated it.
05-13-2004, 04:23 PM
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John, do you have this graph on exel, If i needed to make a function of that curv ....
John, do you have this graph on exel, If i needed to make a function of that curv ....
Again, that graph is in Kg / Hr, Mass over time. But! that depends on the cross sectional area of the housing?
Do you have the Housings diameter?
Thanks.
(trying to rid audis of MAfs)
Again, that graph is in Kg / Hr, Mass over time. But! that depends on the cross sectional area of the housing?
Do you have the Housings diameter?
Thanks.
(trying to rid audis of MAfs)