disabling ESP

[sambb]

just a follow up. There are two ESP fuses. A 10A one and a 5A one. The 10A one is a shared ABS/ESP circuit so I didn't pull that one. Judging by its rating I'm guessing its for the actuators/outputs of the ABS system. I did pull the 5A one though. It illuminates the ESP off switch, brings up the slippery road dash LED and definitely disables the TC. ABS stays active. Not sure yet about ESP interference though. Until I test that on a few corners where I normally get interference, this may not be any different to just pressing the ESP button. I'll keep you posted.

[sambb]

well I went for a very spirited run through the park and I'm pretty sure that the ESP seems to be disabled. There are a couple of spots where previously I could feel the power artificially restricted, but not this time through. With the ESP out of the game its amazing to see feel often it had been intruding. ie very subtley and a lot of the time, not just when you are having a moment. eg there were corners where previously at a fast but safe speed a slight lift would very promptly tuck the nose back into line. I'd just thought that was good handling (and driving haha!) but really I think a lot of that was ESP applying brake force on the inside rear, because it wasn't happening in the same way at all this time. The car feels a lot more real now, its handling traits aren't masked at all and you can really feel its weight, its weight shifts and handling deficiencies more too! A lot of that could be the abscence of TC too though. On really tight hillclimbs where you are throwing the car around alot and with sticky tyres I do think the car will be quicker this way though. I'd probably want ESP induced stability on the high speed stuff.
Also you wouldn't believe the fuel consumption. I reckon with ESP on, the brakes are literally 'primed' against the discs causing drag. The car feels freer and I could cruise consistently in 5th using mid 3's L/100km. I could never get lower than mid 4's before at the very best. I was even able to tootle along (not coasting) at 2.7L/100 at one stage - a big difference. I definitely don't remember fuel consumption being that good with just the ESP off button pressed before.
anyway, i'll keep testing it and then put the fuse back it in and compare it to the ESP off button being pressed to see if its all in my head.

[sambb]

another observation. I put the 5A ESP fuse back in and ran the car with the ESP first activated and then later de activated via the button. I pushed the car pretty hard through a 3rd gear test corner. With the ESP activated the dash symbol flashed and power delivery died in the arse when I was trying to get the power down hard on exit. With the ESP deactivated via the button I had no such dramas and the car just powered out of the corner - no engine power intervention (throttle cut?) and the same as when the 5A fuse is removed.
In both instances the car was on line coming out of the bend and not washing wide so I don't think it was a classic ESP situation. It was a traction control situation which is slightly different in that the wheel slip detected is where the wheel is spinning quicker than the average speed of the car or the powered wheel across from it (with ESP a slide is detected when a wheels speed starts moving SLOWER than the cars average speed).
So ESP button off = 5A fuse removed as far as traction control goes. What I'm not certain of is the difference each has for the ESP. It could be that with the ESP button off that ESP is still active (as everyone more or less suspects) but that its intervention threshold is moved much higher. Having said that I do stand by what I said re fuel consumption. I drove to work with the ESP on this morning and I couldn't get the car to cruise on the flat and especially not up slight hills as economically as it had with the 5A fuse out.
I'm going to try a couple more things:
- after a cruise devoid of braking get out and feel the disc temperatures. I'm guessing they'll be hotter with ESP engaged because I think brake pressure is at play here.
- I forgot to see if left foot braking was possible with the 5A fuse out.
- put the car into some strange positions on the track to see if ESP is capable of throttle cut like the traction control system is. I think it might be...

ie. I had another thought of why my car seems to be a victim of ESP intervention on the track. The car is set up stiff enough at the back to lift its inside rear through uphill and downhill tight hairpins. I think what might have been happening (and what will probably continue to happen unless I find a way to entirely get rid of ESP) is that the airborne wheel hangs in the air long enough to slow down relative to the other 3 wheels in contact with the ground. The system sees this as the car in an oversteer slide (although at the time its railing around the bend) and so starts trying to brake wheels to correct a slide that just isn't happening. Maybe then as a last resort ESP power cut comes in? because at the time there is no front wheel wheelspin.
ill keep you posted

[sambb]

well went for a drive to compare fuse in + ESP button off, and 5A fuse removed. Went through a 3rd gear roundabout with a fixed throttle setting and then left foot braked and in both instances power was cut immediately. I left my throttle foot exactly where it had been, took my foot off the brake and then after a slight delay the car went back to that throttle setting.
This could mean that 5A ESP fuse removed does not kill ESP or it could mean that this is part of the ABS computers responsibilities. I kind of tested that by doing the same thing in a straight line eg no yaw, no steering input and the same thing happened.
Think its just going to have to be at the track to look for any change to ESP function with the fuse removed.

[sambb]

Martin in the "rear brake upgrade" thread wrote:

"(In order to get that extra braking I had to get into VCDS and set the anti lock braking to low/late because the car could now brake harder/faster than the onboard computers though was possible)".

Wondering if any of those well versed in the nitty gritty of VCDS know where/how to do this?
sam

[h100vw]

There might be some coding available in the ABS if you have the knowledge. Along the lines of the weight of the steering on the 6R, which can be changed.

[Martin]

I was modifying the brake settings (in the VCDS brake module) - not the ESP settings

ESP can use both ABS and throttle to aid managing the car
The only way to get totally on top of ESP is via a ECU flash (which is fairly expensive)

I must admit I turned ESP off at the track but only because I was running semi slicks and the car thought I was in trouble

[sambb]

I found this quote in a review/blurb about the 6R 1.4TFSI polo gti regarding the elctronic diff:

"A modern extension of familiar EDS functions is the XDS electronic transverse differential lock, like the one Volkswagen presented for the first time on the Golf GTI. XDS improves handling through fast curves and calibrates the car to be more “neutral”, since it prevents slip of the unloaded wheel at the inside of the curve by active brake intervention, improving traction. This system, standard equipment on the Polo GTI, accesses existing sensor data such as steering wheel angle, yaw rate and wheel speeds. The effect: more safety and driving fun, because the Polo GTI steers even more precisely with XDS"

What I'm interested in is the bit about a yaw sensor. Do the Gav's et al out there have any idea if our car uses a yaw sensor or if not where they are normally located on audi's so that I can have a look? I can't find one on the rear beam which is a pretty usual spot. Altering yaw sensor inputs is pretty do-able with hardware so if we have one it may be something I could look into for changing the ESP threshold.

sam

[h100vw]

I am pretty much 100% there's no Yaw sensor on the Polo.

They are fitted on cars with Haldex though.

Gavin

I found this quote in a review/blurb about the 6R 1.4TFSI polo gti regarding the elctronic diff:

"A modern extension of familiar EDS functions is the XDS electronic transverse differential lock, like the one Volkswagen presented for the first time on the Golf GTI. XDS improves handling through fast curves and calibrates the car to be more “neutral”, since it prevents slip of the unloaded wheel at the inside of the curve by active brake intervention, improving traction. This system, standard equipment on the Polo GTI, accesses existing sensor data such as steering wheel angle, yaw rate and wheel speeds. The effect: more safety and driving fun, because the Polo GTI steers even more precisely with XDS"

What I'm interested in is the bit about a yaw sensor. Do the Gav's et al out there have any idea if our car uses a yaw sensor or if not where they are normally located on audi's so that I can have a look? I can't find one on the rear beam which is a pretty usual spot. Altering yaw sensor inputs is pretty do-able with hardware so if we have one it may be something I could look into for changing the ESP threshold.

sam

[sambb]

Ok I suspected that. I read somewhere that if you had a bosch 5.7 ABS module that it would be under the front seat or rear seat. I'll go have a look now. Any idea what code ABS module we have?

[h100vw]

Ok I suspected that. I read somewhere that if you had a bosch 5.7 ABS module that it would be under the front seat or rear seat. I'll go have a look now. Any idea what code ABS module we have?

VCDS and it's on the page where you connect to the ABS

[sambb]

Just a follow up to all this. What I've found is:

1. ESP on: normal running mode means ESP and the traction control is on
2. ESP off: ESP is still on and only the traction control is disabled. Benefit is you won't get the dreaded power cuts but keep the ESP safety net.
3. pulling the 5A ESP fuse (2nd down on the right of the fuse box) : ESP and traction control is off. ABS still works.

I finally got to test what effect pulling the 5A ESP fuse has. I did it on street tyres on a drying track and also on a few down hill corners locally that would bring it on. With the fuse in you would feel weak ABS pulses underfoot and the car would stay well mannered on the limit. With the fuse out I couldn't generate the pedal pulses and the car was harder to drive on the limit.
What I feel with the ESP still operating is a faint version of the pronounced ABS pulsing that you get in a skid stop test - probably because in the ESP situation it is only modulating the brake on one wheel. I just couldn't seem to replicate this with the fuse pulled so I'm not a hundred percent but pretty sure its the way to kill ESP. Wouldn't mind if others could try it to see what they feel.
Unexpected symptoms are noticeably better fuel ecomomy (on the dash readout) and the fact that the clock resets to 00:00 at each start up. Oh and if you get out of shape, you are on your own!

[kaanage]

Does anyone know which fuse disables ABS?
It would be nice if our models had the ABS disabling switch in the glovebox like the German versions.

[sambb]

I'll check tomorrow. The one I'm talking about is labelled as ESP/ABS and is a 5A. The ABS fuse is a 10 amp but can't remember the number off the top of my head. If you still have it its in the maintenance section of the cars manual.
Not sure if it'd be the same on our car ( but it could be because they are close) but I've read forums where guys with seat leon pulled the ABS fuse and found that it made the brakes quite rear biased. Apparently if you have ABS fitted, the hydraulics run to each corner diagonally from the central module and aren't split front and rear like in a normal system. When you remove the fuse, the biasing may or may not be what you are used to. Like I said I've just read this, not done it but maybe something to be aware of if you try it anyway.

[Blue9N3]

I pulled the abs fuse some time back, kills the speedo too


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