Fuel Segment Swap - Wont work?

[evilstuie]

Hi All,

I'm trying to get my fuel gauge working and it doesn't seem to want to happen.
I have a 2000 LS1 Firebird Fuel Tank and sensor and trying to get the fuel level data to pass through the PCM and via OBD2 to an Android Tablet running DashCommand.

Everything else is displaying, except for the fuel gauge is at 0% and according to the trip computer I have 3080+kms of range.

I've tested the ohms from the sender unit and it is working properly, getting 5v from the fuel pressure wire on the PCM and return value to the PCM also.

The only guess I have is that the OS does not have the required setup to be picking up the fuel data and sending it across OBD2.

The original tune OS was for a 2002/2003 Holden Commodore which was 12225074 upgraded to 1273001 SD Enhanced RTT.
The current fuel system is 92155725 and should be 16264535
The firebird stock OS I'm trying to grab the fuel segment from is 9381344

I load my file in VCM editor, select the stock file for compare, and segment swapper is still greyed out.

What am I doing wrong?

The 2 files are attached if anyone can take a look for me?

P.S. I'm using MVPI 1 unit and my license has disappeared off my devices page. Luckily I had an email copy of it.

Did HPTuners just discontinue support for it?

Anyway, any help is appreciated.

[evilstuie]

Just FYI
The holden commodore had the dash gauge cluster outputted the 5V and return ohm value directly into the gauge, where as 2000-2002 firebird pulled the fuel gauge data from the PCM, but both use the same fuel sender unit.

And I'm using the firebird fuel tank

[blindsquirrel]

The Main OS on both files has to be the same before it'll allow segment swaps. You'd need to find another one with the segment you need but the same 12225074 OS, which is probably unlikely. GM NA vehicles it's easier because pretty often trucks and cars got the same OS used, sometimes across more than one year.

[evilstuie]

Thanks for confirming my worst fear.
That's a bit annoying, and seems to defeat the purpose of a segment swap, unless its just a lazy version of copying and pasting the ohm tables.

So it looks like my only real choice is to license yet another tune file for a stock firebird and then upgrade it to SD RTT and then manually copy over all of my tables again.

I wish I'd have known this before I shelled out cash for HPT and went with EFI live instead. You live and learn I guess.

[blindsquirrel]

There is tons and tons and tons of code in each segment that don't have little boxes or tables you can see in the editor. The editor just shows you a GUI, not the entirety of everything that's in the PCM.

[evilstuie]

Yeah I understand that, but what's the point of a segment swap if you can only swap it with an identical segment/OS?

[blindsquirrel]

The segments can be different, only the base OS has to be the same.

[evilstuie]

So in short, there is no way to get the gauge data working with my current OS/tune?

[blindsquirrel]

I don't know, so far this thread is about being fixated on how segment swaps work.

[evilstuie]

I don't know, so far this thread is about being fixated on how segment swaps work.

Thanks you've been super helpful.

[gametech]

You need to clarify if your first post was mistyped. You specify that you have 5 volts from your fuel PRESSURE on the pcm and return wire. The fuel tank pressure and fuel level inputs are entirely different. If a mistype, disregard this, but if not, recheck that your fuel LEVEL input is not going into the tank PRESSURE input on the pcm.

[evilstuie]

Hey Gametech
Not a mistype, but probably missing context:

The fuel pressure 5v is the reference for the PCM as the sender doesn't appear to have it's own 5v reference available in the wiring, although I did see the Blue C1-8 pin is just straight 5volt.

On the commodores the gauge cluster has the 5v output pin to the sender unit and the ohms resistance return value from the sender.

Fuel Sender unit is going to Red#54 for fuel input, but on the commodore pinout it's not used, I had to put my own pin in there for it.
That's why I suspect the input doesn't register unless the OS is set to use it.

[gametech]

These PCMs are strange. I was looking for scannable unused pins in my 2004 gto computer, and tried the unused fuel level 2 input that is there for dual tank trucks. It already has voltage on it for some reason.

[evilstuie]

hmm, did the group use the same vdo gauges or did gm put something else in? that's the aussie Monaro so it could be the missing link.
Scanner will let me add sender voltage but not level for some reason.

[gametech]

hmm, did the group use the same vdo gauges or did gm put something else in? that's the aussie Monaro so it could be the missing link.
Scanner will let me add sender voltage but not level for some reason.

Fuel level on the gto/monaro goes through the computer. Oddly enough, every time you flash a program change, the gauge cluster gives a fuel gauge error just before it finishes flashing. Just a strange coincidence with regards to this discussion.