Like so many others I have a problem with a C3 Sensodrive Gearbox.
I bought the car having had a new cluch, clutch actuator and gearbox actuator fitted.
The car drives well in forward gears and I quite like it.
However, once it's warm it will not select reverse.
It sometimes takes a couple of attempts when cold, but it does go in, but once it's warmed up it just doesn't select reverse, although it seems to be trying.
Once it won't select reverse, it won't let you rev it at all, and then after you've tried, the snowflake and auto start to flash.
Put it into N and then forward and away it goes.
I had it back to where the parts were fitted and the fault messages were clutch slipping- so they adjusted and also gaer lever attenuation.
I have since had an auto electrician to it who didn't find any faults and suggested along with a second automatic specialist who I went to see that it is a mechanical problem in the box.
I've spoken to a manual gearbox man who thinks the clutch isn't clearing.
I don't have the P code, but does anyone know if this "Gear Lever attenuation" could be causing this problem, or has anyone had a smilar problem with a failing gear lever please ?