Tdi speedo reading wrong

[gusty66]

Hi guys, I have a 2002 ghia tdi and the speedo is over reading by 10mph extra at 20mph and 30mph at 60mph, and so on.
I am currently using the sat nav to indicate my driving speed which is not at all ideal, anyone else had this problem or could point me in the right direction.

[Mirez]

Interesting - How longs it been doing this? I've only seen this when the clusters been swapped out and the coding is incorrect.

[drober42]

Has a drive shaft been changed by any chance? iirc there are different drive shafts for different models with varying ring sizes for the speed sensor pickup, if its the wrong one that would knock you're speedo out, just a thought!

[gusty66]

Hi I have had the car three days and the guy I got it off did not speak English very well so the cars history is vague, I have had a vag com reader on it to check the faults.
1 01315 transmission control module : no communications
2 17948 vehicle speed signal too high, p1540 - 35-10---intermittent
And I haven't managed to check the drive shafts yet.

[Mirez]

Humm it's a manual right? The no comms error is because its an auto cluster that can't speak to the auto controller. You'll need to replace the cluster or flash the eeprom for a manual version. The key question though is why has it been swapped???

[gusty66]

Thank you ror your help, Yes 6 speed manul box, I don't know much about galaxy's as this is first one. So having and an auto cluster in a manual is giving the wrong speedo reading problem?.
I know that the mileage is stored on the ecu but could it be possible that this has been clocked?
And could I just throw in any 1.9 tdi mk2 cluster or do they have diffrent models?
Many thanks

[Mirez]

It certainly sounds like that, the autobox has a completely different speed sensor which gives 0.6 pulses (IIRC) to every one that the manual gives out. Therefore if you put an auto cluster on a manual car it over reads the speed.

The mileage is stored within the cluster, not the car's ECU. Its true that some car's do hold the mileage in the engines ECU but the Galaxy isn't one of those - so the mileage will be that of the car the cluster came out of. That said it may have been legitimately swapped over and it may have had the mileage corrected (not difficult at all) so you can't rely on that as an indication its been clocked.

When you scan the cluster with VCDS, what are the part numbers and extra information listed at the top for the cluster. Ideally, pop the cluster out of the car and read the part number off it - you'll also be able to see what the manufacture date is and whether that tallies up with the age of the car (details on reading the date stamps are in the ref library)

There are different clusters but generally they are interchangeable. Aim for the same year as yours and you should be fine as there was a revision around 53 plate cars that can cause speed issues. Also remember to match the spec, there is a low, mid and high cluster so you'll need to make sure you get a mid or high as you have a Ghia. (The high is generally only seen on car's with Factory NAV in the UK)

[Chrispb]

Just to throw a different light on this perhaps the gearbox has been changed from auto to manual as opposed to the cluster.
check your car details here.
http://www.etis.ford.com/vehicleRegSelector.do;jsessionid=955C283B97AF5D627F5BF05469335059.eccvas509

[gusty66]

Hi guys, more info gained today, went to a scrap yard and swapped out the cluster for one out of a 52 tdi ghia 6 speed and the speedo is still over reading so I put my one back but since doing this I now have a air bag fault light on, do I have to reset the air bags.

[Mirez]

Humm well that wasn't expected... airbags wise, did you turn the ignition on with the cluster removed and/or the steering wheel off? If so then yes you'll need to reset the light with VCDS as its not self clearing.

[gusty66]

Yes i moved the car whith no cluster in so I will reset it tomorrow thanks,
I checked the drive shafts this morning and both front speed regulator rings are 48 slot which correct according to ford the vw and seat use 48 holes.( I was hoping that someone put a vw shaft in)rules that out.
The only thing I haven't tried is the vss on the gear box, it may have been replaced with a 5 speed or an auto one, the ford spares dept at slough shows 3 different sensors but at Ã,£88 it's a massive gamble. Would do you guys think?

[Mirez]

Have you done a full scan on the car? The VSS signal is used on a number of modules so see if they are reporting incorrect speed readings first.

[gusty66]

I only have a basic vag com, I will have a look tomorrow, am I just looking for fault codes?

[Mirez]

yeah just open each controller and have a look at what codes are present, specifically check the park assist and abs controllers and they both use the VSS.

[gusty66]

Used a vag com this morning and checked for all the faults and it's only comming up with are the previous faults that I have posted,and one new one of air bag but I managed to sort that one Thanks again!

[gusty66]

Good news speedo fixed! I was driving yesterday and the trip computer shut its self off so I went back to the scrap yard and took out a speedo my self from a tdi ghia and replaced it and it now works fine apart from the break pad light came on, of which I have the new ones ready to go on, and the cruise controll don't work.

The only thing now is to get the mileage changed as it now is 224000 any idea?

Thanks for all of your help guys on this problem!

[Mirez]

Awesome, so did they give you the wrong one then?

[Chrispb]

  you will need Vag Tacho not Vag com to correct the mileage on the new cluster

[gusty66]

Yes I think that it came from car with a five speed box!
Also I did an mot history check to see what's been going on with the car as i only have the service book as a ref and it's about 40,000 miles over what the car has on old speedo. The car has had a lot of work done to it as you can tell just by looking under the bonnet is got either new or very good head/ inlet man/pipes/turbo and intercooler( lots of money spent).

The speedo was prob replace either as it went faulty or to clock it and make more money,