Bessacarr E660 semi auto box problem

[BrianDJ]

My father has recently purchased a Bessacarr e660 with semi auto box- he went over a few little bumps and it cut out and wouldnt select a gear...the garage suspected a loose cable but they have all been checked...any ideas please before they take the box out and check it?

[Brian Kirby]

Is this van with a Fiat comfortmatic gearbox, or some other? If so, has it been taken to a Fiat Commercial dealership for evaluation? If not, I think it would be wise to do so, as removing the gearbox to check how it is operating sounds to be a very expensive, and ultimately probably unproductive, way to investigate why the electronics that drive it aren't working. If it is a Fiat commercial dealership, you may be wise to ask for a second opinion from a Fiat engineer before any work is undertaken.

 

A computer tells the box which gear to select, and when. It also tells the clutch when to operate. Gear selection and clutch operation are carried out by servo mechanisms. Unless the bumps were very large and caused damage to the gearbox or clutch housings, I'm a little unclear how functioning of the servos or their electronic controls could be investigated with the box on a bench.

 

My wild card guess is that the bumps dislodged the "earth" strap between the engine/gearbox and the chassis, causing pretty well the whole lot to shut down. However, one would hope that possibility is so obvious and elementary that it would be among the first things that would have been checked.

[Mike88]

There are 2 cases on another forum possibly MHF where the wiper mechanism has rubbed against the cable used by the gearbox causing chaffing and cable breakdown. That particular cable requires re-routing. I can't recall anything further details.