Technical Speedo problem !!! for some years the speedometer was erratic and occasionally stuck at zero, now its permanently zero .

[davesmailslot]

Fiat panda 2008 diesel. I have had the car from new and about 5 years ago the speedometer reading became erratic, occasionally it would just read zero until my speed rose above about 5mph, then it would work but erratically. Now its stuck permanently at zero. Had lots of diagnostics and investigations etc done but unable to resolve.
Just wonder if anyone has had similar problem.

 

[irc]

Probably internal to the speedo mechanism if you don't get ABS warning lights. If you have MultiECUScan or similar you can see what the expected readings are (i think you can also test the speedo mechanism, but not sure). If so, swapping the dash is the easiest option.

I swapped dash in my Panda diesel last week as someone in its past had nobbled the MIL light. I'd been waiting for a spare one with lower mileage to turn up for a few months.
Quick mileage correction using MultiECUScan and all good.

 

[koalar]

Test the spedo with software as per two years ago

Otherwise you just will get a long list of possibilities

Dash
Wiring to dash
ABS unit
Wiring from abs
Wiring to abd
Body computer
Body computer software
Front ABS sensor
Front wheel bearing
Bad ground on ABS

And possibly more

 

[davesmailslot]

ABS module swapped out, no change. Instrument cluster swapped out ,no change. I had a garage that specialises in auto electrics generate a signal from ABS module and speedo responded just fine. had diagnostics on system and sensors (ABS) show good.
The only thing that might point to area of concern is that I did have a leak at rear of roof rail which caused the floor behind driver seat to be flooded, just wonder if there might be a connector in that area ?.
Wonder what wheel sensor responsible for speedometer and if there is a circuit diag. to show ABS interconnections.
Thanks for your help.

 

[koalar]

Swap the front abs sensors over

 

[davesmailslot]

Thanks, will have to wait for better weather unless there's connections in the engine bay. Would like to know what wheel
sensor is used for speedometer if possible.
Thanks again

 

[koalar]

It's 100% a front

I have run the car with the front wheels off the ground and the speedo still works

Believe it's the left, but I haven't tested that for myself

Someone had one that have a much lower speed than it should, the odometer still worked but gave lower milage and turned out to be a damaged wire on a front sensor, they reported it as the left, but I don't know whether that's from the drivers seat (normal) or looking from the front or whether LHD or RHD makes a difference

I can't find the thread it's not easy to search as there are so many combinations, it might be under, speed, speedo, speedometer or ABS

When you switch the ignition on does the ABS light come on then go off after it completes it's power on self test

Does the handbrake warning light work correctly when you lift and lower the lever

 

[davesmailslot]

Yes the ABS light works as it should, handbrake also fine.
Thanks again.

 

[chris3234]

You want something like multiecuscab connected up to look at lice data while driving should be able to see if it shows the correct signal from each wheel speed sensor

And hopefully there a option somewhere to see if the ECU recognises the vehicle speed or notif it does that would only leave the cluster or wiring to it

 

[davesmailslot]

I paid for a local company to do a test of sensors and they said it was a "live" test, they had a lap top connected while driving
and according to them wheel sensors ok.
Don't know if this helps but when I turn the ignition key the speedo needle moves from
slightly below zero to zero, then after about 3 seconds drops back to slightly below zero.

 

[koalar]

Swap the two front sensors over

Diagnostic software isn't always 100%

 

[koalar]

Don't know if this helps but when I turn the ignition key the speedo needle moves from
slightly below zero to zero, then after about 3 seconds drops back to slightly below zero.

And with the engine running does it still drop

 

[davesmailslot]

Yes, with engine running needle remains below zero

 

[davesmailslot]

Another strange error from prior to hard fault, speedometer would show about 15 MPH when stationary but if I turned heated rear window on
or main beam or fan to 4, speedo would drop to zero for a couple of seconds then back to about 15.
Should mention also the power steering light permanently on, this was part of the intermittent fault for last number of years but after about
10 MPH needle would move from sub zero and power steering light would go out.

 

[chris3234]

Have you had the earth cables replaced?

 

[koalar]

With out actually doing something

It's just going to sit there none working

With an ever long list of possibilities

It's not a common fault

Just leaving it for years means we have no idea whether any of the these new faults are connected, or have failed since

The front abs sensors are identical, to swap them over and look at the wiring would take no time at all

 

[davesmailslot]

Earth cables original

 

[davesmailslot]

I know this is a long drawn out problem but to date over the last six years I have spent about £750 trying to sort
this out and due to the age of the car I really cant justify spending any more, but other than this I can live quite
happily with this car for another 16 years and that's why as a last ditch attempt I'm looking at this forum.
PS. as I am 77 this year I suppose the 16 years a tad optimistic.

 

[koalar]

You have to eliminate something

Otherwise you will not get anywhere

The simplest first step is to swap the front ABS sensors over

It's just one bolt

Normally you can find someone to help even if they have no experiance

 

[irc]

Whereabouts are you based?
Could be worth finding a MultiECUScan-equipped member nearby who would be willing to plug in and test, read codes, etc. for the price of a cup of tea (or similar).