I have a 98 2.1 TD with 85k miles on it. It has recently developed a fault 
where the speedo stops working - the mileometer and trip are also affected. 
It would seem that the speedo is electronic judging by the speed at which it 
falls when the fault kicks in (its intermittent). Although it usually 
happens from a standstill it can also fail whilst moving and then start 
again a few seconds or a few miles later - there doesn't seem to be a 
pattern.

The only thing that appears to happen at the same time (and this is very 
strange) is that when changing gear from 1st to 2nd the engine seems to lose 
speed faster than normal and smooth changes are difficult. Other gear 
changes don't seem to be affected.

I'm thinking that this could be an ECU related thing. I would put money on 
it not being mechanical.

Any views?

Mark

Mark wrote:

> I have a 98 2.1 TD with 85k miles on it. It has recently developed a fault
> where the speedo stops working - the mileometer and trip are also affected.
> It would seem that the speedo is electronic judging by the speed at which it
> falls when the fault kicks in (its intermittent). Although it usually
> happens from a standstill it can also fail whilst moving and then start
> again a few seconds or a few miles later - there doesn't seem to be a
> pattern.
>
> The only thing that appears to happen at the same time (and this is very
> strange) is that when changing gear from 1st to 2nd the engine seems to lose
> speed faster than normal and smooth changes are difficult. Other gear
> changes don't seem to be affected.
>
> I'm thinking that this could be an ECU related thing. I would put money on
> it not being mechanical.
>
> Any views?


On my Xantia I had a similar problem (but being diesel it didn't affect
the revs). It was down to a faulty gearbox sensor. There's some sort of
plastic gizmo goes into the gearbox and it generates pulses or
something. There is also a plug which goes into said gizmo. Both of
which are failure points. My local Citroen specialist replaced the
gizmo for me. It took him about 20 minutes to isolate the fault and a
similar length of time to replace it. I can't remember how much the
sensor was but the whole repair came to about £50.

-- 
Malc