VY LS1 ECU questions

[niterida]

I have a VY One Tonner with a VY SS LS1 and Auto conversion. I think the SS had a low ratio diff (3.73 or 3.9) and the Tonner has 3.07 as the speedo is 25% out and the auto doesn't change up unless you back off. The ECU has a tune in it and has been locked so I can't even tell if the diff ratio is the problem.
I am looking for the easiest and cheapest way to fix this and thought a std ECU would help but have been told I need the matching BCM and Key.

Anybody know the best way to go to diagnose and solve my speedo and gearchange problems ?

 

[krusing]

You need to change the PPK in the Cluster,
Either a
Tech 2
Autel Unit or similar
or the Site Sponser Software for "Envious Customs".

Based on the size of the Wheels you have, and the Size of Tyres you have fitted,
there are different PPK settings,

 

[niterida]

That will change my speedo but won't change the diff ratio in the ECU which is what I think is affecting the gearchange.

 

[krusing]

Correct, the change of the PPK will cater for different Diff Ratio,
but you need to fix that before the Flash For Cash catch you speeding in error.
I dont think the PPK has anything to do with shift changes,
maybe another member can clarify that ?

I dont know much about tuning, or Auto's as I have always left that to the specialist [Horses for Courses]
But, The Shift changes at set speeds possibly need to be adjust in the ECU, as you have a Tune in the ECU, it will possibly need tweeking.
Also, Some Autos required a Vacuum Source,
I did read somewhere, a member had a shift issue, and found the Auto Vac line had dislodged, so his changes were different.

 

[niterida]

Ok I have found somewhere to have my ECU unlocked for just $75 - then I will be able to see what diff ratio is in the ECU - hopefully it will be 3.73 or 3.9 and I can change it back to 3.07 and solve my problems. Fingers crossed