456GT M seats...

Hi Guys, I've recently bought a 1998 456GTA M - and the passenger seat would not run forwards. It would go backwards (sometimes) but only 'inch' forwards when the switch was operated.
I did the usual, removed the seat and started to investigate - adjusted the cables, checked the 3 microswitches, removed the seat rails (what a pain!), checked the plastic gears in the 90 degree gearboxes and nothing made any difference at all.
But, when I slid back the 'keeper' washers on the 2 splined driveshafts and disconnected the shafts from the seat drive boxes (on the seat rails) then ran the electric motor - it worked just fine!
It seems that there is a forward limiter (timer, counter or something else) which controls only the forward movement of the seat - and my seat believed that it was fully forward and could go no further. It will run in the rearwards direction until the cows come home....
So, I ran the switch to the fully forward position, reconnected the drive shafts to the seat runners - and it works!
A cheap fix to a problem caused by someone not 'initialising' the seat correctly and which will hopefully be of use to someone in the future.
Cheers,
Richard

 

Hi - my car only has seat memory for the driver's side, and from the Ricambi diagrams the M Series cars only have a potentiomenter for recline. Mine only has the recline one. There aren't any leads for a Hall Effect sensors on the rails themselves, so the sensor(s) must be in the dual motor assembly, or as you say, the ecu is counting (forward movement) rotation to establish a fully forward position. When the drive shafts were disconnected, my seat motor would run happily rearwards until the switch was released, I'm assuming that the driver's side would be the same (but I've not recovered enough yet to find out....). Gee, they're fun to play with