Have an emerging issue with my 2011 facelift 1.6TDI. Generally a tidy, seemingly well maintained car.

I’ve only owned it since the beginning of November and from quite early on I’ve noticed it seems quite willing to break traction in 1st gear, even second gear in damp conditions. Aside from the separate question of why a puny 1.6 has so much grunt, as I understand it the car has traction control and should be limiting torque to prevent this and also flashing the skid-mark sign on the dash. It doesn’t.

If I press the ASR button the “skid” light lights continuously and it behaves in exactly the same way.

More worryingly, last night I had to do a full-on emergency stop on a straight, dry road and fully locked all four wheels. No ABS action whatsoever.

And yet, here’s the twist, no ABS or traction control warning lights. Though they do come on with the ignition and go out after a few seconds as expected. Also no codes, at least not with a generic reader. (Will look again with VCDS once I’ve convinced the laptop it lives on it’s not dead…..)

Seems unexpected that two safety related systems (especially ABS) can be non-functional without any warning lights on - any ideas?

VCDS scan & save output
Clear codes
Drive/skid/brake test
VCDS scan, which should show which bits are erroring.

BTW it is of course possible that the fault lies in the wiring or leds on the dash, but I don't believe VCDS will flag that up.

1 hour ago, MikeTheThinker said:

BTW it is of course possible that the fault lies in the wiring or leds on the dash, but I don't believe VCDS will flag that up.

Thanks. Will scan properly ASAP. Above seems unlikely as the lights do come one when the ignition is switched on. I know that in the past warning lights “confuser” boxes existed for fooling MoT testers, but in these days of integrated systems it’s probably easier to just fix the ABS problem!

Car did come with a stray ABS sensor in the glove box (which measures open circuit), which does imply recent previous work….

I'd suspect it's a control unit issue. Best to eliminate the cheap and easy first though. As you've got VCDS - Jack the wheels up one at a time, give them a spin by hand and watch the live data from the wheel sensors, you should get a nice square wave that varies frequency with the wheel speed.

If theres a spare ABS sensor in car its a good place to start. Someone on here had problems with ABS and it was the ring in the bearing that had failed. As previously said jac up car and spin wheels to make sure theres a good signal coming from each sensor. Check the ABS fuse as well. Normally if it blows it pings up a warning but not always. Check that your brake fluid is full as well.

Alasdair

Edited 2 January2 Jan by Alasdair1

Thank you all so far.

Managed to get the elderly and very canterkerous laptop that my VCDS lives on to work long enough to interview the car properly.

Very few codes overall (mostly relating to low voltage and intermittent CAN communication issues) and none at all relating to ABS/TC. Full scan attached -it's wonderfully boring! Logging the output from all 4 wheels showed them all to be working and in agreement speed-wise. Doing the output test on the ABS pump provoked a reaction for each corner (pedal vibrates during the "unlocked" part of the test for each wheel), so I'm at a loss to explain why it wouldn't function normally. Will have to go and find an empty gravel car park to do some real world testing to make sure it's not me that's faulty!

Scan-TMBHT21Z5C2023429-20260104-1420-185320km-115152mi.txt

If pressing the ASR button makes no difference then it does sound like a control problem if everything else checks out. Had a quick google and 00532 came up as low voltage supply. It may not be related but check battery and earths including alternator and connectors etc. If the battery is low due to cold weather etc it can cause problems. Check brake fluid level as well.

Alasdair

Well, seems that since exercising the ABS pump, the ABS system at least is working normally. Not completely convinced about traction control - further testing required.

Traction control now working too. Pleasing, but most odd…… Got me wondering if I’m loosing the plot!

One obvious possibility is poor electrical connections such as broken wire or corroded connectors. Those could have been disturbed during your investigations and are now working - although I'd be inclined to check and clean if necessary.

This point is speculation based on many years of fettling motorcycle brakes; vehicles standing for a long while, especially with aged brake fluid, can suffer from sweat that can rust pistons and caused them to lock up. Could this be an issue with your abs pump?

Thanks Mike. I’ve not done any physical investigations so far. Only the VCDS trawl. I suppose the only physical thing done was the ABS pump “exercise” routine, which does make your second point entirely valid, though I don’t think the car has done much sitting around

I do need to go round the brakes corner by corner to check the mechanicals and also do a full fluid change/bleed. I do usually do this because with any car added to the fleet but I’ve been a bit slow on this one due to its apparent decent history and competition from other fleet members!

3 hours ago, VitesseEFI said:

I do need to go round the brakes corner by corner

A quick and almost painless check is to withdraw a small sample of brake fluid from the reservoir (a disposable syringe is ideal) and take a good look at it (throw it away after - don't put it back!). Any cloudiness will indicate water having been absorbed and any particulates may indicate corrosion/wear in the system. A good comparison is your fluid to a fresh sample of new fluid. They should be very similar in texture and clarity; if not, change.

BTW in case you didn't already know this brake fluid is hygroscopic, which means it absorbs water from the atmosphere over time and would need replacing.

Worth remembering that there are people that have come to the likes of BRISKODA in the past asking how they can Disable the TC / ASR and not have to press to disable, (HOLD THE BUTTON A FEW SECONDS.) There are even those that want the ESP disabled. Then there were Mk2 Fabia pre 2012 without TC / ASR that people wanted to activate, add a button, and also ESP was a cost option on some Mk2 Fabia right up til the EU regulations making it compulsory. Long story short. Check what your model has standard or options and still you never know what previous keepers did or did not do, unless you owned from new...

Edited 13 January13 Jan by Evolution13