Final drive sensor?

[Gryffindor]

My Bee is a 53 reg 1.4i. It has about 63k on the clock but it's missing a few thou...

Some time ago, the speedo and mileometer stopped working. They both just went dead.
This was after the car had been sat for a couple of months due to illness.
I had to clear off several 'are you thinking of dumping this car' flyers from under the wipers! NOOOOOO I AM NOT!!!!

At the same time, whenever I start or cut the ignition with the key, three bleeps began sounding, though there's no accompanying fault message on the MFD.
Same three bleeps as when you open the door with the key still in the ign (which still happens as normal).

I don't know whether the car sitting or the bleeps are related to the speedo fault or not; the only coincidence is that both started at the same time after the car sat, and both continue.

There are no other faults or fault warnings; both the cluster and the MFD still work normally in all other ways.
I have 'got by' by using my road experience and the rev counter to judge how fast I'm going.*
I do want it fixed despite the 'free' miles however, because I want to install cruise control but this fault might get in the way.

I asked a local mech to fix it recently, and to try to be helpful I told him that the problem was once said on this forum to be a failed final drive sensor (FDS) or its cabling. He thought it was to do with a cable drive to the speedo, which of course it doesn't have, but anyway he couldn't fix it.

A few days ago I phoned a Citroen specialist in Welwyn and booked the car in to be assessed this Wed. I described the issue over the phone and mentioned a final drive sensor and my car's age. He also got me to tell him that the gas pedal is cable operated through the bulkhead to a TPS on a bracket mounted onto the osf wheelarch, and then electronic from there on. He then got worried and said that it was hit and miss whether the part needed was still available.

I can't find the FDS mention on this forum now, so was I dreaming it? Could it be the cause of my problem?

Is it possible that such parts are getting thin on the ground now, and should us M49 and M59 owners be reluctantly moving on to the too-modern B9?

Any thoughts welcome, gang.


*Of course this will vary between cars, between gear and diff ratios, and by differing tyre wear, but...
        3rd gear:                              2400rpm = 30mph
        4th gear: 2000rpm = 30mph, 2400rpm = 40mph
        5th gear: 2000rpm = 40mph, 2400rpm = 50mph
        6th gear: sob.
First gear, you're all right; second gear, lean right; third gear, hang on tight... faster!!!!!

[oilyrag]

Not sure that this reply is entirely relevant as it does not address the beeping. In the dim past I had a ZX that used the same sensor as the earlier Berlingo - it sits on top of the diff/gearbox housing and comprised of a small circuit board which read the rotating (magnet?) shaft, which could be withdrawn once the cover nut was removed. The connector has tiny pins and the ZX speedo stopped dead due to a poor connection at the pins, and some years later from a fracture in the earth lead supply to the connector. It's all very fragile stuff, but sprang back into life when fixed.

[cancunia]

On the diesel variants, the speedo sensor is on the gearbox by the driver's / offside driveshaft. I'm guessing that it'll be the same on the petrol versions too. My 1.6 speedo would often stop working when the engine was cold, then start again after I'd put the brakes on. On mine I had to wiggle the electrical connector on the gearbox to make the joint good again.

This video is for a 206, but I think I used it as a guide for my Berlingo.
https://www.youtube.com/watch?v=2pRilRhtR8I

[Gryffindor]

Thanks chaps. You both seem to agree that it is probably this sensor that's at fault, and the YT vid does as well. I just hope it only needs a wiggle!

You have given me a backup plan in case the specialist garage isn't into wiggling: I can now point my local mech straight to it and ask him to have a go.

Or can I? Cancunia, you say the gearbox is on the off side, but I an sure mine is on the near side (too late now to go and check - I have to clock on at 4am too). It is shown on the off side in the YT vid. Haynes says that the gearbox is on the near side (section 7.2 under genl info) but later says that it is on the off side (7.6 under speedo drive).

Also the part itself doesn't seem to have a standard name. I got final drive sensor from way beck whenever. Cancunia and the vid call it a speed sensor, but searching online for that term brings up the ABS wheel sensors. Haynes calls it a speedometer drive, but searching for that mostly brings up the toothed pinion which goes into the sensor as shown in the vid.

The specialist garage thought my car's age was borderline in terms of parts availability - in other words, not M49 vs. M59, but M59 pre 2003 vs. post 2003. Is it possible that the 'speedo drive' system changed from steel cable to electronic about then? As I said in the first post, my gas pedal certainly is a hybrid steel cable/leccy setup.

Anyway, thanks again for your help. I just wish I was still able enough to go leaping under the engine. As someone with amateur electronics knowledge, a PCB which detects a rotating magnet makes perfect sense to me, and poor PCB tracks or connector/wiring connections would be a cinch to fix in themselves.

[cancunia]

Or can I? Cancunia, you say the gearbox is on the off side, but I an sure mine is on the near side (too late now to go and check - I have to clock on at 4am too). It is shown on the off side in the YT vid. Haynes says that the gearbox is on the near side (section 7.2 under genl info) but later says that it is on the off side (7.6 under speedo drive).

Yep, the box is on the nearside of the engine, but the speedo drive is above the offside driveshaft.

[Gryffindor]

Ah, it all falls into place. Thanks Cancunia.

[Gryffindor]

Update: B L Autos in Welwyn GC checked my car over this morning. They confirm the problem is definitely the speed sensor/speedo drive at the back of the right hand side of the engine. They cleaned and wiggled and refitted it but no joy, so a new one is ordered to be fitted next week. I even got a tour of my car's nether bits.

But I was warned that it might not be the sensor - it might be a loom problem, or it might even be a failed instrument cluster. Thankfully the sensor is only £25 from Euro Car Parts, so it's worth a shot (IIRC, £60 trade from Citroen). And thanks to others here I also have a spare cluster. A replacement cluster from Citroen is £660 - trade! B L Autos think Citroen are trying to price old models off the road.

[Gryffindor]

Just to close this thread, since the above my head gasket failed and the car is to be put down without the speed sensor issue being sorted. Sorry gang.

[oilyrag]

Last Rites ? Is there to be a wake?

[Gryffindor]

I am planning one, yes, and on this forum in a week or two - wait and see! But life has to get in the way first. The old girl only has to do one more work run tomorrow, a 20 mile round trip, then she can enjoy her field of grass.

Incredibly, old banger Berlingos seem to be fetching a premium over other models and brands which might be considered better appointed or more attractive - I can only put it down to popularity and demand for a (relatively) basic no-nonsense reliable model which can be a van or an MPV or a camper or...