Mk7 Speedo issue

[rocboni]

Hello,

My 2008 mk7 Transit Speedo has stopped working, all other gauges are working however mileage is not increasing. I don't think the Abs is working as when the wheels spin in the wet I don't get a ESP warning light on the dash. The ESP button lights up on start up and then goes out, pressing it does nothing.

I have seen others have had this issue but no definitive resolutions, what am i best to try first. i presume the above problems are all related. No fuses are blown.


Thanks

[loot]

Get it on ids live data, read the vss and 4 abs sensors etc.

[rocboni]

Thanks, is that something any garage can do or only the main stealers, I know someone with a maxidiag md808 pro will that do the job?

[loot]

I only know ids and forscan will, top makes of diagnostics might but I don't know them.

[knobby1]

Speedo & ABS not working certainly points to a reluctor ring/sensor issue, could even be a doof loom. As Loot says, needs to go on IDS or Forscan.

Lord Knobrot

[rocboni]

So Borrowed a cheapo OBD2 scanner on the off chance it would give me a bit more info, it seemed to read live data, drove about but the VSS stayed at 0 the rpm ect all increased as you'd expect. Couldn't seem to read the abs wheel sensors as it didnt have this function

Should I try a VS Sensor?

Also indicated the the EGR was restricted, the van does have a shudder at a particular rpm and gear, could this be the issue or needs its diesel filter changed.

[twin--turbo]

get forscan and read the codes. the abs lamp should be on though so sugest its been bodged??

[rocboni]

Do I just download it and buy a usb lead? which USB lead have people used?

[twin--turbo]

Think this is the one I got..

https://www.ebay.co.uk/itm/USB-FTDI-Chi ... SwcOVa-R73

Do the download and your away


TT

[Punto443]

Checked the battery?

Corrosion on the big blue/red wire in the underbonnet fuse box?

[rocboni]

Hi,

So I'm getting a fault with the Left front wheel sensor, Left rear wheel sensor and also U0401 Signal invalid from ECM. Are these the cause of the speedo not working?

Running an ABS on demand self test it highlighted no issues.

Driving about with the oscilloscope set to the 3x VSS there was no reading however i am unsure if i was doing this correct.

What do you guys reckon?

Thanks

[knobby1]

Hi,

So I'm getting a fault with the Left front wheel sensor, Left rear wheel sensor.

What do you guys reckon?Thanks

I think you just answered your own question..!!

Lord Knobrot

[rocboni]

I know.. But where do you start replace sensors, test the wiring, where does the wiring go. Is there a diagram?

[loot]

You can unplug the sensors and measure ohms across the pins, about 750 but they should all 4 read similar. Alternatively they should be interchangeable with the other side and you can live test them. I'm a bit dubious about 2 being faulty though, maybe check the abs unit connector.

[rocboni]

I Was planning on testing each sensor through to the ABS uni however was unsure of the pins and how awkward it would be, presume i need to test for short circuits to earth ect?

Hopefully ill get a look at the weekend. Seems a bit easy to fiddle the speedo though if all you have to do is disconnect the abs sensors or is there more to this issue?