speedo intermitenly inop

[rpdiesel]

i have a x reg 406 estate 2.0 hdi and the speedo stop working every now and then, it can drop off wilst driving, not work at all or keep jumping up and down. doesnt seem to matter weather hot orcold or engine revs, any ideas, is the speedo g/box driven or abs as does have a abs fault but wont comunicate with my mates diagnostic computer
cheers rorie

[KozmoNaut]

The speedo is driven from a sensor on the gearbox. When the speedo drops out, do you experience a reduction in engine power? If so, the error is either the speed sensor on the gearbox or the control box.

If you don't have a reduction in engine power when the speedo drops out, the fault is probably in the instrument cluster. Most likely, it's a loose connection or bad solder joint.

[rpdiesel]

It might drop ever so slightly not 100% sure will check. Cheers