There doesnt seem to be a lot of information around on tuning the 5 speed auto box for the GTA and Airtrek. I thought i would start a thread to share what can be done.

The INVECS system is supposed to use fuzzy logic to adapt to your driving style. The definitions show tables to modify shift pressure (voltage/units) and shift maps (Throttle position / speed). There a 5 maps for each with multi condition tables....

One of my pet hates has been the way my car (Airtrek) drops into 5th gear at cruise..even at low speeds of 50 km/h. 5th is way too tall and really should only be used above 80km/h.

Ive had a go of tuning the box shift patterns and now have it so the car only shifts into 5th above 80 km/h. Interstingly the speeds listed in the Rom as the shift points are innacurate (70 in ecu flash resulted in a shift around 80km/h)

Picture shows the modified shift point (4->5) with the original setting at the top.

Anyone understand how the Ecu uses the 4 shift maps or the multiondition tables? Anyone tried using the shift pressures?