Technical where is the speed sender on my X250

[dottyju]

Hi, I hope someone can help.
I have a problem with my 2012 2.3 130 multijet ( euro 5 ) motorhome.

I first noticed the ABS light followed by the EBD light a while later, then realised the speedo was not working ( also trip meters not active, no mpg display, odo not advancing on, cruise control not working ). After a couple of miles the 'engine management light' came on. I stopped a couple of time, restarted the engine and the first time all the 'error' lights reset but returned later.

I now have the ECU and EBD lights on all the time, but did manage to clear the eml light when I reset the ecu code P0500 using multiecuscan program and elm connector.
This was the only error code stored in the ecu but the engine maagement light is now back on ( along with the ABS and EBD lights ).

I understand P0500 is a loss of speed signal but having had a thorough look around the gearbox I cannot find an electrical sender ( not like the one I changed on my previous 2.8 jtd anyway ).

The only sensor I found has about 4 or 5 leads connected and is on top of the gearbox ( next to the gearbox vent pipe/cover ) and looks like a spark plug ! with a 4 or 5 way square connector on top.
Is this a 'road speed sensor/sender' ???
Its a sod to get at and right where water cascades onto the engine via the wiscreen scuttle so its going to be a supect but I dont want to attempt removing it until I am sure its the part i'm looking for.

Any information on where the sensor is and its part number or description would be great.

I enquired with a parts dealer who cannot find details of the speed sensor part in the plans for my model and is asking me to look for it and get back with any part number on it ?

 

[varesecrazy]

Hi, I hope someone can help.
I have a problem with my 2012 2.3 130 multijet ( euro 5 ) motorhome.

I first noticed the ABS light followed by the EBD light a while later, then realised the speedo was not working ( also trip meters not active, no mpg display, odo not advancing on, cruise control not working ). After a couple of miles the 'engine management light' came on. I stopped a couple of time, restarted the engine and the first time all the 'error' lights reset but returned later.


I enquired with a parts dealer who cannot find details of the speed sensor part in the plans for my model and is asking me to look for it and get back with any part number on it ?

Hi, you'll have a form of speedo drive., but it may well be a wheel speed sensor is actually an ABS rotor on a Hub,

look HERE;http://eper.fiatforum.com/eper/navi...INDOW_ID=1&KEY=HOME&EPER_CAT=SP&MAKE=F&SBMK=T

Charlie - Oxford

 

[corcai]

Sender is on the diff casing, next to the breather is reversing switch but can't think why it would have that many wires.

[edit]Actually I think the speed sensor on the 250 might only be there if you have a tacho. In which case its abs over can bus.

Multiecu scan plus kkl cable and read the abs errors.

 

[dottyju]

Hi All, An update... ( Thanks Corcai for some pointers, its got me a bit further along with diagnosing this fault ).

I'm a novice with the Multiecuscan program I bought recently but read the manual and tried with the elm interface and the Yellow adapter to interrogate the ecu modules with the following info :-

P0500 code ( intermittent ) still exists but can be reset for a while but comes back.

Doing a DTC scan with the yellow adapter shows a ' Body computer' fault code B12C9 - Vehicle speed signal incorrect ( from NFR ). I could not see that this fault code can be reset, its there all the time.
Saw NFR listed in the ABS perameters list as being the 'Brake system Node ? ( hoped it might mean Nearside Front Right sensor ! but doubt it ).
Googled code B12C9 but cant find anything about it ?

I also spotted in the parameters list for the Bosch ABS 9 i have fitted that the speed sensor type is Type DF11s.
Googled this and found its a Bosch 'hall effect' wheel abs sensor used in ford cars but not Fiat !
Also saw in the ABS module parameters list separate wheel speed displays ( which show 0 mph when stationary - Thought it might be worth driving with the laptop attached to see if the 4 wheel speeds are displayed and all the same ? any thoughts?

This is getting complicated, does anyone have any ideas of where to go look next or do I need to bite the bullet and take it to a Fiat agent ?

 

[varesecrazy]

Hi All,

This is getting complicated, does anyone have any ideas of where to go look next or do I need to bite the bullet and take it to a Fiat agent ?

FIAT will be expensive, and pot-luck if you get any great knowledge,
look for a local FIAT/ Alfa specialist.
the one in Oxford always had Ducato's in.., shame they are now shut

 

[corcai]

Also saw in the ABS module parameters list separate wheel speed displays ( which show 0 mph when stationary - Thought it might be worth driving with the laptop attached to see if the 4 wheel speeds are displayed and all the same ? any thoughts?

This is exactly what you should do next. if one is reading different you may have a split reluctor ring, iron filings on the sensor, if it reads zero unplug the sensor and measure the resistance, (could be missing reluctor ring too.

 

[MJT81]

Hi DottyJU, have you got to the bottom of this? I'm having exactly the same issue on my Stilo JTD, same error and speed is measured from ABS. Please let me know if you've found the solution!

Matt

 

[lm04]

Don't get too confused with the speed sensor. Not complicated - hall effect is just the type of signal they use trade call it a 'pulse', its' just a speed sensor!

Firstly, you can check the pulse by jacking up and moving a wheel - or driving a few feet once wired to a tester meter. Should be something like 1458p/1650m margin as a rough guide. That would mean 1458 turns of a wheel per mile. So every turn of the wheel, you should get a pulse.

Put in gear, turn a wheel and watch the number rise on your tester. Of course the calibration could be out. It is not uncommon on these to have faulty VSS Sensors. This will equate in speed being slightly inaccurate initially. It sounds odd, but 0.2 can equate to a large deviation in speed and distance. In 100 miles, you would register 80 etc. or 120 depending if under to over.

You could just throw caution to the wind and buy a new VSS, they are not expensive! Around £15 margin normally, and it would be fresh and accurate.

I am not convinced that your dash may not be to blame, however. That said, a new VSS isn't a bad thing.

 

[adlarplant]

Had a similar problem with my 2011 2.3 ducato lost all dash function everything worked ie. indicators lights etc. but wasnt showing on dash plus speedo tacho not working no actual codes showing i finished up resetting the body computer by unplugging at the fuse box counting to one hundred then plugging back in no further problems Cheers adam

 

[dottyju]

Finally got it sorted...
As we are going roaming in France/Spain for several weeks early May onwards I needed to get it fixed quickly so took it to a Fiat specialist ( Imperial Commercials, Ashbourne Road, Derby ) .
Took a week or so as the problem diagnosis was complicated with Fiat Technical help being needed.
It was diagnosed as the Bosch ABS main unit ( ABS Pump ) not outputing a correct speed signal.
A replacement new unit was located and fitted ( its behind the nearside headlight between the fuel filter and bulkhead/inner wing ).
The cost of the unit was £1400 + labour + diagnostic time + VAT ( around £2400 ! )
Imperial Commercials submitted a 'goodwill' claim for me even though its some 18months out of warranty ( but only 19000 miles on the clock ).
luckily Fiat agreed to pay for the total cost of the ABS module and labour costs, leaving me with just the 2.5hrs diagnostic time it took to determine the problem to pay ( just over £200 ).
Really pleased with the outcome but the potential cost of failures of major modules such as this is frightening !
I could be wrong but I think another clue to this fault, which I didn't think relevant at the time ( besides the warning lights/messages, loss of engine power, no speedo, trip meters, external temperature reading not showing etc ) was that the whirring/buzzing sound that occures for a second or so when you turn on the ignition ( after a period of rest ) was absent. I assume the buzzzing sound is the ABS pump priming ready for use if needed ?

Thanks to all those who contributed suggestions on this forum.

 

[andydiver]

Result. Well done all round, including Flat themselves.

 

[corcai]

The potential cost of failures of major modules such as this is frightening !

Was that almost £800 labour to change an ABS pump?! Including bleeding/flushing and testing I would expect 2-3 hours tops.

Certainly main dealer costs are frightening, an independant garage would have fitted a used pump or had the pump repaired by the likes of BBA Reman or ecutesting.co.uk. for a fraction of those costs.

 

[dottyju]

Hi Corcai, The issues were that the results from the ( more expensive than my toy ) diagnostic tester did not indicate an ABS module fault leading the engineer to look for other things. Also the 2.5hrs dianostic time was an accumulation of carrying out suggested actions by Fiat technical on a number of calls to them and waiting 1 or 2 days for them to provide details each time of the next step.
So if you add £1400 ( 1700 inc vat ) 2.5hrs diagnostic time and 2.5 hrs ? to change the part @ £60- £75/hr ( or whatever they charge ) it does add up.
I agree in hindesight one might expect them to go straight to the root of the problem but I would have been really pissed if they had changed expensive parts to later find it was a cheaper problem to fix ( as i've read about on some blogs where repeat vists back to the dealer were due to changeout of parts was carried out as a process of elimination ).

I was surprised at the difficulty in finding a Fiat specialist able to do this repair, the nearest in Nottingham could not take the work as their only fully trained Fiat engineer was on holiday, The dealer at Derby was not able to fit it in ? and actually recommended Imperial Commercials. I found out later that actually the Derby Fiat main agent send a lot of 'fault' work to Imperial Commercials.

At the end of the day they fixed the fault and it only cost me a little over £200 and I'm really chuffed with that.
I wonder if other Fiat main agents would have pursued a 'goodwill' claim on behalf of a customer ( and one who has never bought a vehicle from them or had one serviced by them ! )
I would be interested if anyone knows of a reliable 'indi' Fiat specialist in the Midlands for future reference ?

 

[nyhlen]

I'm in the same situation.
Have had trubbel shouting on my mobile home the last weeks and are now waiting for a new ABS unit to be installed
Heard in our mobile home club - HUSBILSKLUBBEN - that there are two mor members who had this.
It is all on mobile homes year 2013 and 2.3 l 130 ps engines
/Thomas

 

[Oldpeculiar]

Just a word of thanks to dottyju for highlighting his problems (and solution).

I have just had exactly the same problem on my 10,000mile, 2012 Ducato motorhome: ABS warning, EBD failure, no speedo, Engine management light, no cruise, no trip info and, strangely, no external air temperature reading. Engine went to reduced power mode and my diagnostics lead me to a failed "vehicle speed sensor A".

After a little research, I discovered that a discrete 'vehicle speed sensor' does not exist on this model, but is replaced by an output from the ABS computer which accepts wheel speed sensor inputs from all 4 wheels and computes a signal for speedo etc. I suspected the ABS computer had failed and dottyju's post added further weight to this.

I contacted Imperial Commercials at Mackworth, Derby and was able to chat to a really helpful technician called James. I booked the 'van in for diagnostic work to confirm the problem and was met at service reception by James who explained the system to me in simple terms and said he would check all wiring and diagnostics and then contact FIAT on my behalf.

Two days later, I picked up a completely serviceable van fitted with a brand new ABS unit by James and, best of all, FIAT agreed to pay for the cost of the unit and fitting charges - I just paid for the diagnostic time, relieved and grateful that the cost was nowhere near the £1800-£2000 mark I had feared.

I can thoroughly recommend the team at Imperial Commercials - they were courteous, extremely helpful and yielded great results in short time: Thanks to James and colleagues (and FIAT for their response)!!