[Mick-R]

Hi All

I have a T5 1.9 TDI 57 plate. The ESP light comes on after around 15 minutes of driving. As soon as I cycle the ignition switch the light stays out for another period of time. But last night i was running the Van on the drive and the light came on without driving, after about the same amount of time. I have heard that this can be a control module within the ABS module that needs replacing. Any one any ideas ?

thanks for your help

****

 

[toucanspeed]

Get vcds and look at the codes, it could just be a wheel sensor

 

[Mick-R]

Thanks,

just seemed odd that the light came on when i didn't travel anywhere this time, if it was a wheel speed sensor wouldn't it be an ABS warning light that came on ?

 

[T5 TDI]

As TS says you need to get it on diagnostics. The ESP system uses the ABS sensors to determine wheel speed. The ABS system might be quite happy if it just looks like a wheel is spinning occasionally but the ESP might make a different calculation if it doesn't think it can respond correctly. You would be very lucky to find the fault without plugging it in as a start.

 

[Mick-R]

Thank you

I will plug in and see if i get any codes

thanks for your help

 

[T5 TDI]

For the best chance to fix it make sure to get a print out of all the fault codes from everything on the van (especially the CAN gateway and ABS) plus all the other controllers. T:

 

[Mick-R]

Hi Again

Right i have plugged in and it shows a fault code of 01314 - check fault codes in Engine control module.

So i checked the ecu and it comes up with an Alternator feedback communication problem. So i would think the ecu is looking for a certain voltage back from the alternator but is getting the wrong voltage.

I have checked that i have 12v on one of the wires going into the alternator, so i have a feed, but i am not sure what voltage i should have on the other wire as its showing milli volts at the moment. is this right ?

Any help would be great

Thanks for your help

 

[T5 TDI]

The small (blue?) wire is the DF wire which is the load sensing wire. I don't think you should see 12v on it but not certain. There should be continuity from the alternator to the J519 box on that wire.

I remember from some problems I had on mine that it goes from the alternator via the Ebox under the battery and on to the J519 box which is underneath the dash on the drivers side. You can look at the J519 with VCDS. It comes under 'Cent Elec'. See if it has any codes. They can fail and cause problems or it could be the wire itself broken somewhere.

 

[triffic]

Right i have plugged in and it shows a fault code of 01314 - check fault codes in Engine control module.

What code reader are you using? If it's an OBD2 reader there's a good chance it won't even be able to read fault codes logged by the ABS controller. The ECU fault code may be completely unrelated to your ESP problem.

 

[Mick-R]

I am using a Wurth Snooper which is suitable for Manufacture specific. I have found another thread with symptoms and codes the same as mine and one of the guys had a 120Amp alternator fitted and his symptoms and codes appeared in both modules. He replaced this with a 90Amp Alternator and ll was back to normal. So i checked my Alternator which had been fitted just before i bought the van and Lo and behold its got a 120Amp alternator fitted. Have you seen this problem before, where you need to fit the 90 Amp alternator even though they say the 140 Amp is compatible ?

 

[Mick-R]

The small (blue?) wire is the DF wire which is the load sensing wire. I don't think you should see 12v on it but not certain. There should be continuity from the alternator to the J519 box on that wire.

I remember from some problems I had on mine that it goes from the alternator via the Ebox under the battery and on to the J519 box which is underneath the dash on the drivers side. You can look at the J519 with VCDS. It comes under 'Cent Elec'. See if it has any codes. They can fail and cause problems or it could be the wire itself broken somewhere.

I believe one wire should have 12v disconnected with ignition on, then show around 7v when connected. I was quite sure the other wire when the engine is running should show millivolts, but i have nearly system voltage on this one.