5vdc source for fuel pressure transducer.

[nukem]

I purchased a 5vdc 0.5-4.5v 0-100 psi transducer to monitor fuel rail pressure in my 04 Silverado 6.0 swap. I recently purchased the MPVI2 pro kit I will be monitoring through. My question is where can I get a 5vdc signal to drive the transducer? Or would I need a separate power supply for this?
Thanks.

[orange ss]

plenty of 5vdc circuits from the pcm...TPS, EGR, A/C, etc and even some that are not used..tap into one of them

[nukem]

I guess that?s my question though.
Pardon my ignorance but if I knew where the unused 5vdc sources were in the PCM I wouldn?t have asked the question.

[blindsquirrel]

You can usually run more than one sensor off a single +5v supply wire. Just tap into an existing one. Internal in the PCM there isn't a dedicated supply for each individual sensor, it's one (or a few) voltage regulators that split internally and feed multiple pins.

If you want to find a separate +5v pin that's unused in your harness, you'll have to backprobe the blank spots in the PCM connectors. Just comparing pinouts from other applications that used a P59 isn't enough, there could be pins that are unused in ANY application but still provide what you want.

[blindsquirrel]

In a 2004 Silverado 4.8/5.3/6.0 P59, there are only 4 +5v ref pins in use. C1 7(IPC), 45(RPS), 46(FTP), 48(MAP).

In a 2004 Silverado 4.3 P59, there are 5 in use. C1 pin 8 is blank in the V8 harness, in the V6 it's the +5v for the TPS (DBW trucks get TPS +5v from the TAC not PCM). Backprobe that cavity and see if you have +5v. You may not, that pin may be turned off when using a DBW/V8 calibration. Don't know until you check it. If you just really think you need to use a separate pin for your new sensor.

[blindsquirrel]

And another thing.

In the V6 P59, the TPS signal return is at C2 pin 24, and it's unused in the V8 harness. That pin may be an 'unsupported parameter' in the scanner when using a V8 calibration but you should check it, if it works that may be an easy way for you to read/log your new sensor.

[nukem]

Thanks so much!

[blindsquirrel]

Since this is a swap, are you using any of the EVAP stuff? If not you can use the fuel tank pressure sensor wiring for both powering and reading your add-on sensor.

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