Recently whilst driving I've had a few occasions where my ESP has cut in in (in the form of applying the brakes) part way through a corner.  They've always been fairly open-ish corners taken at speed (motorway sliproads, that sort of thing).  I'll be going round, steady on the power with no significant correction of the steering wheel when all of a sudden the brakes will apply themselves and the ESP light flashes - obviously having the brakes suddenly, forceably and repeatedly applied halfway round a corner isn't my idea of fun

Has happened going round both left and right bends so can't be isolated to one side of the car.

This has only started happening since I upgraded to 312mm brakes and before then I could go round the same corners at the same speeds without this happening.

The car doesn't feel like it's about to understeer (far from it) - I've been able to provoke understeer before and this isn't what it's done in the past or certainly not as aggressively in such a benign situation.  The suspension is upgraded quite a lot (Eibach Pros, Koni FSDs, Poly bushes, Neuspeed rear ARB and lower strut brace) so is usually more than capable through the corners

The front tyres are Dunlop Sport Maxx's (so not cheap budget tyres) and have a fair bit of tread left on them before the wear markers.

Any suggestions as to what's happening and why my ESP thinks it should be kicking in?  Have I just reached the limit of what it's happy with?

I'm sure it must be related to the brake upgrade as it's too much of a co-incidence, but can't think how

Before you say it, I know I could just turn the ESP off or go round corners slower, but that doesn't really solve the problem, it just hides it!

Jon.

well what is ESP thats the question to ask.

Heres the video answer and the one where they go around the bend prob is for you

<p><a href="http://flash.revver.com/player/1.0/player.swf?mediaId=HTe3s1tQA4w&width=480&height=392&affiliateId=0&javascriptContext=true&skinURL=http://flash.revver.com/player/1.0/skins/Default_Raster.swf&skinImgURL=http://flash.revver.com/player/1.0/skins/night_skin.png&actionBarSkinURL=http://flash.revver.com/player/1.0/skins/DefaultNavBarSkin.swf&resizeVideo=True">http://flash.revver.com/player/1.0/player.swf?mediaId=HTe3s1tQA4w&width=480&height=392&affiliateId=0&javascriptContext=true&skinURL=http://flash.revver.com/player/1.0/skins/Default_Raster.swf&skinImgURL=http://flash.revver.com/player/1.0/skins/night_skin.png&actionBarSkinURL=http://flash.revver.com/player/1.0/skins/DefaultNavBarSkin.swf&resizeVideo=True</a></p>

View original media here: http://www.youtube.com/watch?v=HTe3s1tQA4w

Cheers Hotboy  - I know a couple of bits and bobs about hte ESP and what sensors it uses, but not much. 

What's puzzling me most is why it's suddenly started kicking in after I upgraded my brakes - it's not like I'm going round corners any quicker with the bigger brakes on, so what difference can it have made that the ESP thinks it need to slam on the brakes in the middle of a corner? 

Next time it's dry it may be time to dust of those 'steel balls' and turn the traction control off and see what happens

Jon.

Wot are the rear tyres like for Tread depth

How do they compare to the fronts?

what sort of mm difference do you have front tyres to rear tyres?

well i wouldn't say you need balls of steel to go without TC in a Golf TDI! try it, you get a bit of tyre squealing an thats it. it almost makes the flashing esp light and application of the brakes seem a bit too much on the safe side if you know what i mean.

sometimes in high speed cornering i get a bit of flashing as it's aplying the rear brakes, but it defo does not cut power. it only cuts power if it sees the front wheels are about to spin,

logically speaking it must be something you have done when you were fitting the brakes, have you double checked the wires to the front abs sensors?

the ESP system has been known to mess up when the tracking is out, or even when new tyres are put on the front with very worn rear tyres. done any of them recently?

fenwick458:

well i wouldn't say you need balls of steel to go without TC in a Golf TDI!

Anyway, rear tyres are pretty much the same in terms of tread depth - none are appreciably more or less worn than the others. One is a michelin pilot sport and the other is some cheapo budget thing and all have been on the car since at least january.

The ESP isn't cutting the power at all, it's just applying the brakes - It's definitely the front brakes it's applying it to - I'd say it was being applied on the outer wheel as you go round the corner, although this could just be me feeling it more as this is the wheel that's loaded up in the corner.  I could understand it happening if I was suddenly applying more power halfway round the corner or making a big correction with the wheel, but ithat's not the case.

The tracking was last done a couple of months ago after the wishbones were out - I'd say it'd probably benefit from being done again, but it's not horrendously out.  Am at PSI Tuning on saturday, so may get them to check it if they've got time.

Logically you're right about the brakes, but I can't think how it could affect it. The abs sensors are fine and the abs light isn't coming on at all, just the ESP and it's only under this one condition.

I'm stumped on this one so keep your thoughts coming!

Jon.

Could it have anything to do with the bigger brakes adding more unsprung mass to the two front wheels? The two front wheels now have more momentum? Clutching at straws here but just a thought.

It could be due to the mismatched tyres.  But this would not explain why the problem has just cropped up.

Tyres from diff maufacturers may not be exactly the same rolling radius.  Plus you have a Mich pilot sport one one side which is a very good tyre and a cheapo budget thing on the other...

wellsy:

It could be due to the mismatched tyres.  But this would not explain why the problem has just cropped up.

Tyres from diff maufacturers may not be exactly the same rolling radius.  Plus you have a Mich pilot sport one one side which is a very good tyre and a cheapo budget thing on the other...

I know mismatched tyres aren't ideal, but these are on the back and the ones on the front are matched. 

If it were down to the mistmatched tyres I'd expect it to happen more often going round corners one way  than the other, but that's not the case.

Jon.

My car's esp kept cutting in during fast sweeping corners (typically motorway slip roads) 

after lots of messing about,  it turnt out to be the fact that the front tyres were new, and the rears were half used.  The difference in rotational distance was enough to confuse the ESP into thinking the front axles were travelling at different speed to the rear axles.

Problem was solved once I replaced the worn out tyres.

Gti Fly:

My car's esp kept cutting in during fast sweeping corners (typically motorway slip roads) 

after lots of messing about,  it turnt out to be the fact that the front tyres were new, and the rears were half used.  The difference in rotational distance was enough to confuse the ESP into thinking the front axles were travelling at different speed to the rear axles.

Problem was solved once I replaced the worn out tyres.

Could just be co-incidence that it's happened after the doing the brakes I s'pose and I've just worn them to the point where that would start happening.

Jon.

 Changing the Discs to 312 mm should not cause any problems, my setup similar to yours, FSDs, Pro springs, Poly Front Bushes and 312 mm brakes.  I have not had any problems.  What I did notice is when I changed the discs you can get debrie off the old discs/caliper falling on to the phonic wheel at the rear of the hub.  I had to brush mine clean with a soft brush, the rust particals could have an effect on the ABS sensor which the ESP uses to measure wheel speed.  It could be worth whipping off the discs and checking the sensors are clean.

Right here's the vital statistics:

• OSF - Dunlop Sport Maxx  4.9 - 5.9 mm tread remaining
• NSF - Dunlop Sport Maxx  4.9 - 5.8 mm tread remaining
• OSR - Event Budget Tyre 6.0 mm remaining all over
  
• NSR - Michelin Pilot Sport 4.7 - 5.2 mm remaining

As suspected, they're all fairly close so I'm a bit skeptical about this being the cause - not convinced enough to shell out for 4 new tyres all round anyway!

Think am going to have to turn the ESP off and see where the car's wanting to go to try and pin this one down, unless anyone has any other suggestions?

Thanks for all the help so far

Jon.

gttdigolf130pd:

 Changing the Discs to 312 mm should not cause any problems, my setup similar to yours, FSDs, Pro springs, Poly Front Bushes and 312 mm brakes.  I have not had any problems.  What I did notice is when I changed the discs you can get debrie off the old discs/caliper falling on to the phonic wheel at the rear of the hub.  I had to brush mine clean with a soft brush, the rust particals could have an effect on the ABS sensor which the ESP uses to measure wheel speed.  It could be worth whipping off the discs and checking the sensors are clean.

How soft a brush are we talking to clean them?  Am a bit wary of doing more harm than good as I know they're pretty sensitive.

If it was the ABS sensor though I'd expect to be getting some kind of irregular response from the ABS under heavy braking and at the moment I'm not.  I had all kinds of strange responses when I ended up with an intermittent connection to one of the sensors after suspension fitting (this has all been sorted ages ago with a new loom).

Jon.

Could be down to differing GRIP levels in this case,

Or

Poor alignment/tracking etc

Or worse case faulty ESP motion sensor (this is what I was possibly wrong with my car,  but subsequently it turnt out to be the worn out tyres).

I really can't think of any other issues.   unless one of the ABS/speed sensors on a certain axle is slightly out, which means it's not measuring the rotation correctly, therefore sending duff info back to the ESP/ECU brains

 Jon,

I take it non of the sensors have gotten wet at any time, I had a prob with mine where water was running down the cable into the connector. in my case it was just setting a warning off that there was a fault with the sensor but am wondering if there might be some in the sensor/switching box that when you cornering speed/angle hits a certain amount it's setting it off.

Just a thought that's all

Hope you can get it sorted.

Greg

 I just used a 1" paint brush, the only reason I would look at these first is that it is the only part of the ESP system you have been near when you changed your brakes.  It could be at yaw sensor has coincidently failed at the same time.  The only time I've had trouble with my ESP is when I had the Cruse control fitted and the muppet at the main steeler did not fit the steeering wheel straight, this tripped the ESP off.

Chris

Right, just been on the vagcom and no faults coming up, so unless it's one of the sensors kicking out duff information, that rules those out.  So the plan at the moment is:

• See what happens with the TC off
• Get tracking / allignment checked
• Check ABS sensors and clean if necessary
• Erm....... hopefully it'll be sorted by the time I get to this point because I've got nothing more at the moment!

Will be the weekend before any of this gets done, but will let you know how I get on

Thanks to everyone for the help so far

Jon.

hmm sounds odd, the only thing i can think it can be is something you may have knocked while fitting the new brakes as i had no issues when upgradeing my 312's to ECS Stage 5 and upgradeing the rears to 312mm's.
i have never had issues with rolling diamaters being an issue and i always 3/4 wear the fronts then swap for the rears.
Hope you get to the bottom of it.

Quick report of todays findings - Damp roads today so was easier to provoke at slower speeds, so didn't need those steel balls after all

Anyway, it predominantly seems to do it going round left hand bends - think it's only done it once going round a right hand bend. 

Switched the traction control off halfway home and coming off a roundabout roundabout and the back definitely seemed to come round a bit too much as I turned left to leave it - not stupid and not out of control, but you could definitely feel it move, so I'm beginning to wonder if it is my cheapo budget right rear tyre after all.

Possibly a stupid question, but when the ESP cuts in, does it ever do it's thing gently in the background without you really noticing, or will the light always come on on the dash? 

I'm just wondering if what's happening is the brakes have always been doing it but the effect has been far more gentle with the old worn smaller discs, pads and fluid.  At the same time as the 312 upgrade the rear discs and pads were changed along with the brake fluid - I'm wondering if it's just doing what it's always done but the effect is far more pronounced now when it does apply the brakes because they're so much sharper after everything being changed? 

PSI are checking the steering and suspension on saturday and I'll be checking the ABS sensors sometime over the weekend too.

Jon.