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- Apr 9, 2014
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- 2,304
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- Tartu, Estonia
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- C?ID=195131
This is bothering me for a long time. And i can't seem to figure it out.
Note: If i talk years, i mean when the changes occurred in EU.
For cars til 2010 it seems they use this type of system, so if fuel level moves, voltage on pin T36/17 or t32/1(on 4motion also pin T36/16 OR T32/3) changes and as these systems tend to use fixed amperage so the resistance could be calculated with ohm law. R=U/I. On pin T36/18(t36/23 or t32/4) the voltage seems to be fixed because of the resistor in place, so also fixed resistance.
The fuel level seems to be calculated via the difference in the resistance. If we guess the fixed resistance is 90 ohm for full tank, so 45 should be half tank.
Am i right so far?
Now what i don't really understand is 2011+ cars. It seems that both resistances vary because ground wire is not in the fixed side as it was on the 2010- cars.
Although the pinout seems fairly identical the wiring doesn't. What i mean is the t3ai/1 goes to sensor ground in both cases, but in one case it connects to, i guess it's resistor wire output and in other to in the sliding part of the fuel sensor.
I'm totally lost here, help me guys and girls.
Note: If i talk years, i mean when the changes occurred in EU.
For cars til 2010 it seems they use this type of system, so if fuel level moves, voltage on pin T36/17 or t32/1(on 4motion also pin T36/16 OR T32/3) changes and as these systems tend to use fixed amperage so the resistance could be calculated with ohm law. R=U/I. On pin T36/18(t36/23 or t32/4) the voltage seems to be fixed because of the resistor in place, so also fixed resistance.
The fuel level seems to be calculated via the difference in the resistance. If we guess the fixed resistance is 90 ohm for full tank, so 45 should be half tank.
Am i right so far?
Now what i don't really understand is 2011+ cars. It seems that both resistances vary because ground wire is not in the fixed side as it was on the 2010- cars.
Although the pinout seems fairly identical the wiring doesn't. What i mean is the t3ai/1 goes to sensor ground in both cases, but in one case it connects to, i guess it's resistor wire output and in other to in the sliding part of the fuel sensor.
I'm totally lost here, help me guys and girls.