The speedo needle on my 1998 406 wagon has begun to fail intermittently. It just stays on "0" for random lengths of time, sometimes flicks into life instantaneously, then dies again, sometimes works fine--did the latter when tested by an auto electrician earlier this week (he replaced a globe behind the clock & a fuse enabling the temp. display to work again--but speedo is unchanged). When indicating "o" speed, the odometer doesn't change either. When the speedo needle is functioning, the odometer turns over normally. Have phoned the local service dept., who have no experience of 406 speedo failure. So anyone out there got any ideas of the best order to start looking at things? thanks Bryn Parry Tasmania
I suspect the plastic gear inside the gearbox has shed a few consecutive teeth. My 405 did this a couple of years ago. Remove the speedo sensor/cable* assembly from the gearbox near where the righthand drive shaft leaves the Gearbox. The gear is a push fit on the end of the sensor. New ones are less than 5UKP. Jack up the right hand front of the car has much as possible, support on a stand.This will minimise oil loss from the gear box. *this applies to both electronic sensor and cable driven speedos Good luck Bob
It's more than likely to be the sensor itself. And usually it messes up the ECU which is situated behind the glovebox.
I have the same problem with my 1996 406 Exec Turbo (petrol) - the speedo has been working on and off for the last few years! I've had the gearbox sensor changed (£50), but that didn't change the problem in the slightest. I'm loathe to take the car to a Peugeot dealer, since I reckon they'll just fleece me for a new instrument panel - £££s. Given the car is basically worthless now, is there anything else I can try before giving up? Does anyone know how much a new instrument panel for the 406 is?
I presume it's an electronic speedo. Check and clean the cable connections - if that doesn't work it might need a new speedo (i.e. part of instrument panel - hopefully). I would try either a local independent place or an auo-electrics specialist.
Cheers for the tips Chris - it is an electronic speedo (a Sagem, I think). Do you mean the cable connections behind the instrument panel i.e. remove, clean and refit? I'd love to think that Peugeot would supply just the speedo assembly, but I have this strange feeling that they'd only supply the whole shebang. I have read somewhere that the plastic gears within speedos can wear over time, which would give this kind of fault - teeth only meshing some of the time - but I wonder if an electrics specialist would be willing/able to strip the speedo down to fix it. Can anyone recommend a good auto-electrics place in London?
You said you have had the gearbox sensor changed, but what about the actual ECU, which is fitted on most models. Situated up behind the glovebox, it's always best to change the two in pairs--cost around 90 pounds, I think, but you should be able to get it at a scrappie.
Nigel, I'm not sure what the Speedo ECU looks like. I've scoured the Haynes manual (which doesn't officially cover the 2.0 Turbo petrol model, but can the speedo mechanism be that different?!), and the only reference to any ECUs in there are for Air-Con, Cruise Control (which I don't have), and the main engine management unit (which I doubt you mean since a) it's in the engine bay, and b) is likely to cost more than 90 UKP!) Should I just take the glovebox out and poke around?
If you poke your head up behind the glovebox ( you don't need to remove it, but you will need to remove the insulating trim under the instrument panel below the glovebox) with a light, you'll be able to see the ECU. The connector is toward the bottom, I think coloured white or brown. You should be able to just pull it down with moderate force. The 90 pounds is with the gearbox sensor.
Haynes manual (which doesn't officially cover the 2.0 Turbo petrol model, but can the speedo mechanism be that different?!), and the only reference to any ECUs in there are for Air-Con, Cruise Control (which I don't have), and the main engine management unit (which I doubt you mean since a) it's in the engine bay, and b) is likely to cost more than 90 UKP!) Should I just take the glovebox out and poke around? Hi Ron, The device that you are looking for is the speedometer transducer box, it is located under the glovebox it has a white socket on it that is held in by a locking latch. They cost £23 approx inc vat.... if this has gone it is non repairable you will need a new one. Let me know how you get on... *_*_*_*_*_*_*_*_* D.
Thanks D, The car is due to go in for its MOT next week, so I'll get them to change the transducer then. Fingers crossed that it will work, since I've just read on topgear.com that a new speedo head unit is £650!! Basically that would make the car worthless, since I'd only get about £1500 for the car...
Ron, can you let me know if you got asnywhere as I seem to have the same problem. I've noticed that if I keep the heaters on full, it works better and quicker, so I suspect it could be inside the car, rather than on the actual gearbox. Can you let me know how you get on, Cheers Neil Take a look at my e-mail address before replying direct, the transducer then. Fingers crossed that it will work, since I've just read on topgear.com that a new speedo head unit is £650!! Basically that would make the car worthless, since I'd only get about £1500 for the car...
