MAP Voltage vs. Tablecolumn
 

Hallo,

can anyone tell me how i can determine the map voltage at which the ECU accesses a specific table column?

i know that column 15 is about 3v because thats NA maximum voltage but the rest?! only guessing, not exact.

can anyone help?

ECU is a European PW0.

Re:MAP Voltage vs. Tablecolumn
 

Re:MAP Voltage vs. Tablecolumn
 

Hallo,

thanks for the Info but that was not what i'am looking for.
i want to know what table column are accessed at a specific give voltage not the pressure that the sensor has at a specific voltage.

i ask that because all the MAP scales that going around in pgmfi forum and elsewhere are not 100% exact in my oppinion so i can't get the colum by pressure for sure.

because noone has determined the pressure scales for the PW0 ECU with 100% error free... i think that are all simply guesswork no exact values.

Greets
Malte.

Re:MAP Voltage vs. Tablecolumn
 

...but...

Knowing the voltage that is the pressure value tells you the column headers.

The 0-3v linear voltage is scaled to a 0x00-0xFF value used by the processor.

Each column contains a lower and upper boundry. IE, column 1 is 0x00-0x0F, column 2 is 0x10-0x1F.. so on and so forth for 15 columns.

From the information that was posted, you should be able to calculate the headers....

Re:MAP Voltage vs. Tablecolumn
 

if this is true (from where exactly is this information?) then you are right.

are you sure that the scale is exactly 3,00 Volts = 0xFF?

and 0xFF (3,00v) must corrospond to exact 1046mbar abs. pressure?! right?

i found a pressure to voltage table that says that the stock map sensor has:

1100mbar=3,15v
1000mbar=2,87v

so i calculated: 3 Volt = 0,0028*Pressure + 2,87 Volts
((3 - 2,87) / 0,0028)+1000 = 1046mbar

do you think thats correct?

if yes then i have a problem solved!

Greets
Malte.

Re:MAP Voltage vs. Tablecolumn
 

I learned that information directly from the PM6 based table lookup routine in the ROM. It's the same as all of the OBD0 ECUs which are restricted to 8-bit math.

You can disassemble the ROM and check for yourself..

As for your calculations, I'll ASSume they're correct. I didn't do them myself.

Re:MAP Voltage vs. Tablecolumn
 

Ok thanks... i will give it a try