doubt i can tell you anything if you're an e.e. it's basically a mapped
system that compares input from the sensors you say with its map.
[although i don't think it measures vacuum directly but minute changes
in angular velocity of the flywheel]. the map, as you probably know, is
not alterable unless you re-chip. it does however retain some
statistical information on driver habits to "learn" to a small degree.
for hills, my 2000 civic would labor in top gear [economy mode] until i
manually dropped it to 3rd. after a few times of manual dropping, it
now does it on its own and keeps it there until it's truly ready to
change up again. quite intelligent really.

i've never done the same for engine braking but in my experience the
standard mapping is quite adequate. it holds it in a lower gear if the
rpms are increasing without throttle so just one moderate brake
application should be sufficient.


Richard Lane wrote:
> jim beam wrote:
>
>> why?
>>
>> Richard Lane wrote:
>>
>>> Apparently grade logic downshifting occurs when certain combinations
>>> of braking, rpm and vacuum occur. Can anyone tell me what these
>>> combos are for a 2000 Ody?
>>> Dick
>>
>>
>>
> Why? Principally in order to know how many times to apply the brales to
> induce a downshift but also (being a retired EE) intellectual curiosity.
> Dick