TC lockup & 749 ECU

[Roger Heflin]

On Sun, 15 Oct 2000, Barry Tisdale wrote:

> Anybody know if the recent thread on TCC lockup may apply to the 749
> (Syclone & Typhoon) ECU?  Is there a mandatory lockup in this one too?  My
> twiddling w/ the TCC tables doesn't have any effect on the lockup @ 70mph.
> 
Gm always seems to have a TCC lockup no matter what parameter.   It is
a single parameter outside of the tables, and is not related to
anything but speed (throttle is not checked).   

On my car (93 Z28) the stock setting was 95, and it was not a problem
until I put parts in the car that changed the torque curve enough that
95 was a bad place to lock it.

The address for the parameter in mine is located very very close to
the tables that control part throttle lockup, so you may be able to
guess where it is.

I don't think the parameter would be called prevent unlock, that is
probably referring to one of the 4 paramters at the top of the table
that control exactly how and when the tables are used, and is
completely separate from the lock no matter what parameter.

Check the flowchart at:

http://users.hit.net/~rah/EDD3_EF37.gif

The flowchart is pretty ugly, the notes may explain more of what sort
of parameter GM seems to always use in their vehicles.

And some notes at:
http://users.hit.net/~rah/disassnotes.html#TCCLOCKUPTABLE

				Roger

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