Not sure of any connection, but the "mapping" is different in high n low, basiclly you need much more travel on the loud pedal to reach desired revs,
Got somthing to do with better throttle control when on rough terrain
the first time i drove wifeys TD5 90 i had some embarrasingly failed hill climbs due to this reason ( i found out this info at a later date )
Just a thought :-k