Can you tell me what parameters the Alli uses to command grade braking? What has to occur in what sequence? I was thinking about this driving home today. Thanks
I have a grade brake question
- Thread starter Whitetail Addict
- Start date
Ive been asking about this for a while, and how we can make it better. Because at least on my truck, grade braking is totally hit or miss. SOmetimes it works really aggressively, sometimes it completely sucks and wont downshift at all.
As a whole, in my oppinion, the grade braking logic that allison has programmed into the TCM is pathetic IMO.
basically it looks at speed, rate of decel, brake usage, closed throttle accelleration, throttle %, and how long the drivers foot has been off the throtlte and on the brakes. I have not gotten a straight answer from anyone on what exact numbers/values the parameters are. I suppose because its a secret.
ben
As a whole, in my oppinion, the grade braking logic that allison has programmed into the TCM is pathetic IMO.
basically it looks at speed, rate of decel, brake usage, closed throttle accelleration, throttle %, and how long the drivers foot has been off the throtlte and on the brakes. I have not gotten a straight answer from anyone on what exact numbers/values the parameters are. I suppose because its a secret.
ben
The strategy in T/H is extended shift points and early converter clutch lock. It does not release the converter clutch on lift throttle as in O/D. Auto matic down shifts occur with the converter clutch applied which gives you your compression braking and the downshift speeds are governed by speed sensor and programming.
Thanks for the input guys.
Does this work the same way in normal mode? Mine is hit or miss in normal mode, although now it works more after resetting taps. Works fine in t/h.
Can you change any parameters in tcm tuning which will affect when it commands grade brake? i.e. tbiq, or base torque tables.
Does this work the same way in normal mode? Mine is hit or miss in normal mode, although now it works more after resetting taps. Works fine in t/h.
Can you change any parameters in tcm tuning which will affect when it commands grade brake? i.e. tbiq, or base torque tables.