Hart_Rod

iTrader: (3)

Has anyone when been able to get their VHX speedo to work with a E38 ECM? I have a Speartech harness that pulls the speedo output from X1J1 pin 57. When I wire that directly to the VHX box (speed sender), I dont get any pulses. However when I have my HPTuners scanner connected via the OBDII port, the speed output displays perfectly on the scanner. Any suggestions? Thanks,

Rob

EDIT: I forgot to mention this is for a 6L80 and you can't use the Dakota Digital signal generator.

1989GTA

I believe HP gets the signal off the GMLAN wires. There is communication between the transmission TCM and the E38 and the VSS signal is part of it. Some have tapped into that wire with success. It did not work for me. Without looking it up I think pin 57 may be an input from wheel sensors.

Hart_Rod

iTrader: (3)

Thanks GTA. I got that info off of HPTuners website:

http://www.hptuners.com/forum/showth...one-of-the-OSS

I'm working with Dakota Digital trying to figure it out. I'm sure it's something simple, either in the TUNE or something on the control box. I know I shouldn't worry about this, but it makes doing the tune a lot easier when you can see how fast you are going from the gauges and not having to look at the laptop.....

1989GTA

Thanks for the link. I will look into my setup.

1989GTA

Update: I looked up my notes and I did add a yellow/black wire to pin 57 of J1. I also have checked the "serial" output on HP Tuners in the speedometer section. Car is still at the paint shop so I can't physically look at it. I will check it out when I get the car back. Seeing as I have to 2011 Corvette tune this might work.

Hart_Rod

iTrader: (3)

89GTA would you mind sending me a copy of your tune?

Rob

1989GTA

I will see what I can do. It will be a first for me.

futureuser

iTrader: (1)

My e38 works fine with dakota vhx. As long as you can get it to pulse, the gauges will calibrate.

Hart_Rod

iTrader: (3)

How did you set your tune up to make it pulse?

EDIT: Just ready your build. You have a 4L60E, I have a 6L80, totally different beast...

Hart_Rod

iTrader: (3)

GTA - thanks for the file. I set mine up like yours, but still a no go. I did verify that there was nothing wrong with the DD control box by connecting the sender that they send with the kit and using my electric drill to turn it. It worked as advertised, . So that leaves the wire or the tune. I did a continuity check on the wire and double checked the pin location and all checked good. Now I just need to find an oscilloscope and see if the computer is putting out the correct signal on the wire.....

1989GTA

I wonder if a 1K pullup resistor from 12vdc would be needed for the speedometer signal? I know one is generally needed for the tachometer.

Hart_Rod

iTrader: (3)

I can try that. Do I just wire it inline with the input wire to the speedo?

Rocketrod

iTrader: (2)

I used Autometer gauges my harness was originally wired to use a signal out of the TCM, but it wouldn't work. I had to tap directly into the VSS signal coming directly out of the trans for it to work. I would have to look at my notes to see if it was the hi or low signal, but I try them both, separately, and see if it helps. I also notice the PPM setting in HP Tuners had no bearing on how the speedo functioned.

1989GTA

The 1K resistor would "T" off the wire and the other end of the resistor would go to a 12v source. Hartrod, if you do get it to work be sure to post what you did and the settings in the ECM.

Rocketrod: I tried that with my Speedhut speedometer and that did not work. I tapped off the high signal. Apparently it works with the Autometer gauges.

I do have a solution as I bought a Speedhut speedometer that works with the GMLAN wires. However I want to play with this and see if I can get it to work on the standard gauge. I am using the X1-57 pin.

Hart_Rod

iTrader: (3)

Ok guys, I finally got the solution for the problem.

Chris - I downloaded the new version and made the changes - you da man!!! The speedo now works correctly!!! Thanks again,

Rob

1989GTA

Just as I tore my dash appart to put in the Speedhut speedometer that uses the GMLAN signals. I can still put the old one back in I guess as it is still apart. I would rather use the signal out of the ECM. That way I can use HPTuners and without messing up the speedometer. What do to, what to do?

Hart_Rod

iTrader: (3)

Make sure you download the latest version of HPTuners so you can make the change that is required. Let me know if you need any help.

1989GTA

Thanks. Downloading right now. I assume the port on the ECM is J1-57? I will go ahead and put the old speedometer back in and see what happens.

1989GTA

Ok, just down loaded the latest version. Went to speedometer setup and it has for "output source" the following :
1. Disabled
2. Rep TOS
3. Serial.

I assume number 3 (serial) is the one to use with this latest version of HPTuners? Thank you for getting to the bottom of this problem.


Edit: By the way the latest version is now 2.24.476.

Hart_Rod

iTrader: (3)

Here's how I have mine setup:

EDIT: I downloaded it yesterday and it says 2.24.469... strange....guess I just need to update mine about every 2 weeks...