Goldhawg

iTrader: (7)

Search says a bunch of people have the problem of the E38 ECU reading 158 MPH using pins 71/72 on J1 connector; aftermarket speedos seem to take the signal just fine. Well I too have that problem, with my 2010 L96 (LY6) that I kept VVT & E38 ECU but have a T56.

Anybody have any counsel on how to solve? I just wanted the ECU to be able to have VSS for driveability at low speeds.

Appreciate any leads so I can pass to my tuner.

Thx!!!

1989GTA

What about the LS3 program in the new Camaro's. They run a stick shift and the E38 ECM. So the question would be how does GM do it on that model?

71403

1989GTA is on the right track

http://www.lt1swap.com/2010camaro_ecm_pinouts.htm

Goldhawg

iTrader: (7)

Ok, so the pinouts are still the same--71/72. So what else does one need to do on the tuning to make it work?

1989GTA

I don't know but can you tap into the orange/black wire of Pin 71 and run it up to your speedometer.?

Goldhawg

iTrader: (7)

In my case the speedo issue is not a prob; I went with the GPS speedo. Believe others successfully used the VSS signal off tranny before going to ecm to drive their speedos. I am only trying to solve the problem of the ecm seeing speed @ 158; I want the ecm to know the true speed as I've been told that will help low speed driveability.

garys 68

iTrader: (1)

So I'm guessing your issue is the 17 tooth speed reluctor (in the program) vs the 40 tooth reluctor (in the trans). Is the e38 that different from earlier ones. Brendan over at LT1 swap was able to recalibrate my gen III ecu from just a couple pulse/rev, up to 39 pulse/rev with the T10 no problem.

tiresmokinV8

iTrader: (6)

I too have this problem with my ly6 e67 t56 swap.

85MikeTPI

iTrader: (9)

http://www.hptuners.com/forum/showthread.php?t=36796

Are you using HPTuners? I thought CAM had this working with the beta copy?

Goldhawg

iTrader: (7)

He advised me (subsequent to this thread being created) to contact HPtuners and get the beta version which should fix. So I've contacted my tuner to do that since he has the HPtuners license. Hopefully this will solve. The thread above is also useful; I'll send him that link too.

garys 68

iTrader: (1)

Interesting read, thanks for the link.

-TheBandit-

iTrader: (1)

Great link 85mike. Looks like I may need to shove a VSS into my TH400.

-TheBandit-

iTrader: (1)

Here's another thread with some discussion on the issue, but no resolution.
http://www.hptuners.com/forum/showthread.php?t=35546

tiresmokinV8

iTrader: (6)

So far the fix seems to be to add a tcm inline between the trans vss and the ecu,

-TheBandit-

iTrader: (1)

Can you elaborate on that? What connections are and aren't used for the TCM?

tiresmokinV8

iTrader: (6)

I was going to try it before swapping to a stalled auto this winter so Ive been talking back and forth with my wiring guy current performance and heres what he said.
"It wouldn't be that tough to do. 1 ignition power, 1 battery power, 1 ground, and interrupt the CAN Bus wires (2 in, 2 out). Then, move the VSS wires to the TCM, and run 1 more wire from the TCM to the ECM.

I tried it on my bench while feeding a signal in to the TCM, and it took care of the 158mph thing. Once I took the TCM out of the circuit, it immediately defaulted to 158. I emailed HP Tuners about looking in to it.
I did the same thing with an ECM from a GM Crate motor with no TCM, and it works fine. So I emailed 2 files to HP To see if they can find where the difference is to make it work."

I have wiring pinouts for a t42 tcm if you want.

85MikeTPI

iTrader: (9)

But aren't you using a different PCM (E67)? The OP and others were asking about the E38 which already has the discrete VSS mod in HPT.

tiresmokinV8

iTrader: (6)

Oh, yea the guys on hpt have been able to get it to work without a tcm on e38 ecu by switching the trans type to manual in the more updated hpt beta. I tried it with my e67 and it didnt do anything.

Goldhawg

iTrader: (7)

My tuner wasn't able to get it w/switching the trans type to manual; emails to Chris @ HPTuners regarding the hpt beta went unanswered. But I've had the car back from tuner over a week; maybe he's responded. Sure would like the soln.

buddyholly

I have the same problem with my Chevelle L76/TR6060 manual combo. I have tried the HPtuners beta switch and I still am showing 158mph. My car runs fine this way but I would really like to find a solution. I also have the same problem in my LY6 swap in my '76 GMC truck. I have assumed that since it reads 158mph at all time no matter how anything is wired that is thinks it is getting a LOT of pulses from somewhere no matter what is actually going on.