Adaptive Shift Not Working?

[samh_08]

I've been working on my tranny tune (T42 controller) and have been logging shift times. I notice that there is always a shift error and it doesnt seem to 'adapt' itself do the desired shift time.

I have the stock values in for all the shift times and pressure, with some TQ management removed (15% in low load areas).

Is there a way to see if its actually adjusting something to achieve the desired shift time? Or am I missing something else..?


Thanks :cheers:

[samh_08]

Bringing this back to life because I now have a T43 controller doing the same thing. Is this possibly an EFILive bug, or am I missing something?

[joecar]

What year/model/vehicle (in each case for T42 and T43)...?

[samh_08]

T42 was a 2008 GMC Sierra, and T43 is a 2011 Chevy Silverado. Both have 5.3L engines controlled by an E38.

[joecar]

It was working before...?

[samh_08]

When I was stock, yes. I was scanning the trans before I ever tuned it and the shifts followed the desired shift time. Now it'll just shift however it feels at the time with no signs of adapting the shift pressure.

Does the trans have to be a certain temp before it learns or something?

[joecar]

When you flash, the trims and taps get cleared.

Yes, TFT has to come up to temp, and some drive pattern/cycle has to be achieved before TAP starts learning.

[samh_08]

Temp must be the issue then. Its been 30*F here so the trans temp only gets around 100*F. Do you happen to know what temp it needs to meet?

[joecar]

I don't know the temp, I'll have to dig thru a few service manuals to see what they say.

[samh_08]

Dig anything up Joe?

[joecar]

I just see brief explanations of what it does... not all models have it... I don't have any service manuals after 2005/2006.


Try getting TFT up to operating temp and see if it starts working again.

Also check for any DTC's.

[samh_08]

Part of the issue is that 'Desired Shift Times' dont ever change from zero with the T43. Known bug? Shift times show up, but every desired shift time says 0.0, or n/a

[joecar]

Do you have some logs I can look at...

and some tune files.