pillagenburn

iTrader: (2)

Let me give you guys some background:

I'm using HPTuners version 2.23 beta.

I put a LY6 (smaller L92) into my Firebird with a m12 t56 out of a 2004 GTO. The problem is that the speedo will not display even remotely correctly. I have tach working, oil pressure and level working, coolant temperature and everything. This is all on factory electronics with the e38 ecu.

When I'm going about 20mph the speedo will peg. When I'm going 5mph the speedo will think im going 70; I'm off by a wide margin.

I've tried setting everything to (what I believe) are the correct values. Ive looked at the stock tune from a 2004 GTO and copied the VSS input pulses and inputted my 3.42 gear ratio with my correct tire size (24.92 for 17" tires with 315/35/17 tires). I've tried setting insanely high values for everything (6.1 gear ratio, 40000 pulse input, smaller tires etc) and still cannot get the thing to read correctly on the cluster speedo. The speedo in HPTuners reads pegged to 158mph when trying to log and I deleted the .os file. I've tried adjusting the wheel speed pulse ouput average but that has no effect whatsoever. It seems that everything I try (either setting correct values or incorrect ones) does not work. The VSS is wired into the ecu correctly and the output is coming from the only speed sensor output I can see on the e38 ecu pinout for my vehicle. Everything is wired correctly... I've seen other posts about the 2004 GTO vss being an oddball, but does anyone have any ideas??

I'm using the 2.23 beta version of HPTuners... could this be a problem with the beta software not setting values correctly or something? Not to blame the software, it's an absolutely incredible product, but I just want to find some answers. If anyone has ideas, I'd be most appreciative!

Also, I find it strange that there is no specific "vss output pulses per mile" section in the speedo area for my e38 but on other vehicles there is... is this by design? Also, does the e38 possibly have a vss aux output somewhere? If so, where?

JonCR96Z

iTrader: (33)

Post the tune.

pillagenburn

iTrader: (2)

will do. hopefully tonight.

pillagenburn

iTrader: (2)

here's a link to my thread, with .hpt tune file, on the HPTuners message board.

http://www.hptuners.com/forum/showthread.php?t=26404

any input would be appreciated!

Grip

Just curious if you ever resolved your VSS issues?

I was told to wire the VSS wires thru the TCM and then to the ECM. Wiring it directly to the ECM causes the issue you are seeing.

Dd you find this to be true?