3.0L GUIII Boost Sensor/Sender

[soundfx]

Hi all,

I'm wanting to custom make a display panel for various things on my 3.0L. I've only just bought the vehicle and am pretty new to diesels, have an OK knowledge of engines, and have an pretty good technical mind.

The first thing I want to do is measure the boost pressure from the turbo. I'm assuming there is a boost sensor already on the vehicle as I've read about the car going into limp mode if it overboosts. Am I wrong?

Where is the boost sensor?

Also, what signal does it send back to the engine management computer? Is it a voltage or current modulated signal?

Cheers

[boots]

http://www.nissanpatrol.com.au/forums/showthread.php?6702-MAF-sensor-cleaning-what-about-boost-sensor Hope this helps mate

[Rumcajs]

The boost sensor is mounted directly on the front top side of the intercooler. See attached picture what the thing looks like (ignore the intercooler location)
Why reinvent the wheel see
ECUTalk (http://www.ecutalk.com/ecutalk.aspx) software and cable or the LCD display to read exactly the Engine ECU reads.
Also remember that readout is as absolute pressure= atmospheric+boost and I believe it is as a voltage not current modulated signal whatever that means (do you mean PWM or pulse width modulated signal) that is reference voltage at ~5V and return signal at linear rate.
Cheers

[soundfx]

Thanks for the info.

My brother bought me an Arduino (http://arduino.cc/) as a gift and I'm wanting to utilise it on my GU. Hence wanting to "reinvent the wheel". The ECUTalk software looks like a pretty sound investment, I'll defiantly be getting the cable. I'll probably still have a crack at mucking around with the Arduino though, just for the fun of it.

Do you know what the scaling of the 5V signal is, eg how many psi per volt?

[Rumcajs]

Sorry, don't know that exactly at this hour, probably best way to figure it out is to use compressed air with regulator and measure voltages as the pressure changes to get the values individually.
Found the little reference saying that approx 40 kpa (5 psi) is between 0.6-1.0 Volt. above 0 kpa boost voltage (remembering it is atmospheric pressures) which should be between 1.9-3.0 Volts, here it is .....
Cheers

[soundfx]

Thanks Rumcajs

I might take it to work and set it up on a test rig there. If I get some decent figures I'll post the results here.