406 Speedo intermitent

[b19grr]

Hi All,
My speedo is playing silly buggers at the moment, generally when I first start it won't work at all then after an undefined period of driving it'll wake up and usually works consistently from then on - occassionally it'll drop to zero for a brief period before returning to normal. I haven't been able to determine a definite way that will get the speedo working, it just starts working when it feels like it. I had a theory that doing a full lock turn got it working, that was shot down when I was driving along a dead straight road and it just died on me. I've also tried deliberately driving in pot holes to shake things up with no result as well (thinking a questionable connection somewhere).

Any ideas, or does any one know if this is a known fault? Will no doubt just have to drop it off at the local garage and be told they couldn't find anything wrong for £50!

It's a V reg 2000, V6 estate for reference, 83k on the clock.

Cheers,
Rob

[pstruck]

If it's anything like the coupe, then there is a little box of tricks up under the dash on the passenger side called a 'speedo interface module'. These regularly start to play-up, or give up altogether and leads to the symptoms you are describing.

Only solution is to replace the module.

Of course it may not be this, but it should be the prime suspect in your line of enquiry.

[b19grr]

Thanks mate, a 'speedo interface module' certainly sounds like a very likely suspect doesn't it!

Cheers,
Rob

[pstruck]

Have a look at this link... www.peugeot406coupe.com/phpBB2/viewtopic.php?t=3865&highlight=speedo

It is for the 406 Coupe, but much of it should still apply. The exact part number may differ, but you'll get the idea.

[B19GRR]

HI,

Sorry for the slow reply, doesn't time fly!

Thanks for the link I've done a bit of searching over there, seems like there are possible answers, I just need to confirm if my car uses the easy DIYable under-glovebox sensor, or the trickier gearbox mounted jobs. I suspect the latter as it's the newer engine.

Will hopefully get a bit of time this weekend to prod about under the dash.

Cheers,
Rob

[combemarshal]

I had the same thing on my Xantia, same part almost, just different size drive wheel which I swapped over, the shaft had broke that connects the drive wheel to the sender but would sometimes work.
The sender is on top of the gearbox/dif held in with one bolt, piece of piss to change, but you may loose a little gearbox oil if using ramps rather than a lift, the drive gear should come out of the sender unit and there should be a shaft that it slide onto, the drive gear has a hollow square middle that the shaft goes into