55 chev LS3 conversion E40 T42 mph problems

[AutoRehab]

Thanks to all
I have a 55 chevy car ls3 with 4l65e trans, ecm and tcm are from 2005 corvette vin 1G1YY24U855108969.
Have been able to tune engine with no problems,
my problem is the trans shifts way to soon, 4th gear at 20mph. when looking at trans data with my snap on verus, it shows 158 mph when actual speed is 45mph, Dakota digital dash reads properly as well as ECM, just not TCM, when in the efi-live trans cal for the speedo there is a check box for corvette, transaxle etc, when I uncheck it and apply, close the box and flash pcm.
Then I go back in, and the change did not stay, the box is checked again

[Taz]

It makes it difficult to offer reasonable suggestions - given that you did not post your tunes.

[AutoRehab]

I have been trying to do some other math calcs, the Dakota digital reads 1 mile at 14,000 pulses, the tire size on car is
24/45/18
gears are 4.10
4l65 trans
attatching engine and trans tune
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[AutoRehab]

Also when I try to click on speedo calculator, I get this error



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[joecar]

You have to have installed V7 and V8 while logged in as Administrator, and you have to run the software while logged in as Administrator.

[AutoRehab]

I have now logged in as admin, the error message is gone.
I have re flashed TCM with cal posted in this reply as well as screen shot of my snap on verus and speedo.
Speedo is accurate to ECM as well as actual speed with GPS Speedo.
One only thing I didn't mention before is speed sensor was bad and I replaced it with one from 2002 Camaro A/T.
Didn't think this is the problem being ECM and speedo read correctly.
As I mentioned before the Dakota Digital Pulse count on a measured mile was 14,000.
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[AutoRehab]

Thanks for the help, I have posted some new info if you have more advise.

Thanks, Don.

[CalEditor]

You have to have installed V7 and V8 while logged in as Administrator, and you have to run the software while logged in as Administrator.

Thanks for helping out Joe

[AutoRehab]

Just wanted to add I don't have vehicle working yet, any help appreciated.
I did not perform install, just trying to help repair. car was brought to me believing trans was bad. ( was just speed sensor) customer has been trying to get tuned for some time now.
was told yesterday to check grounds and dual power to T42 tcm as it could be why it is not holding cal. their wiring is hidden very well and hard to get to, any thoughts before I tear into that?

[CalEditor]

Just wanted to add I don't have vehicle working yet, any help appreciated.
I did not perform install, just trying to help repair. car was brought to me believing trans was bad. ( was just speed sensor) customer has been trying to get tuned for some time now.
was told yesterday to check grounds and dual power to T42 tcm as it could be why it is not holding cal. their wiring is hidden very well and hard to get to, any thoughts before I tear into that?

Brian had contacted me about this.
AC and I go back to 1986

[CalEditor]

Post your current file please

[CalEditor]

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It looks like you need to get the correct sensor also

[AutoRehab]

I installed corvette speed sensor with no change.
I have installed operating system and calibration from my wife's 2006 SS Trailblazer this morn, speedo reads within 6 miles or so now.
Now I will Start tuning on TCM again.
Here is current tune.

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Any suggestion on what to change would be great, this is my first time.

[CalEditor]

The Corvette speed sensor placement is in the rear diff and the reluctor ring is incorporated into the outside area of the ring gear. The reluctor spins at the same speed as the wheels.
On a Camaro or truck the VSS in at the end of the trans and spins at drive shaft speed, before the rear diff.

Bryan says you have a 4L80 trans is this correct?

I would built out the trans calibration to match the trans used.
The engine calibration needs to be setup correctly as a non Corvette application using a Corvette or SSR/T-blazer SS file

As you can see the VSS is setup for a Corvette.

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[AutoRehab]

4L65e Trans
Im getting P0723 with the corvette sensor, reinstalling Camaro sensor now to see if code goes away

[CalEditor]

4L65e Trans
Im getting P0723 with the corvette sensor, reinstalling Camaro sensor now to see if code goes away

if the sensor is not on the rear diff and is in the trans it needs to be a Camaro type. Bryan did not mention that this was in a 55 chev. If you have a 4l65 then I would just run the T-blaser SS calibration as a base file