# Is my haldex not working?



## timvgti (Mar 14, 2007)

My 180bhp TT quattro has quite a lot of Nm's after a remap (220bhp|250lbft) and today, with the rainy weather, I noticed that my front wheels slip when accelerating hard/full in first, second (and sometimes also third) gear on straight roads and when accelerating in/when coming out of a corner (ESP/ASR turned off).

I think this isn't normal, is it???
How to check my haldex is still working?
How to see/feel/notice that my rear wheels are also driven)?


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## John-H (Jul 13, 2005)

Pull your handbrake to the first click, so the warning light comes on. That disables the Haldex. Can you tell the difference? - you should get more wheel slip.


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## timvgti (Mar 14, 2007)

John-H said:


> Pull your handbrake to the first click, so th ewarning light comes on. That disables the Haldex. Can you tell the difference? - you should get more wheel slip.


You say 'MORE' wheel slip?
I haven't tried it with the handbrake to the first click, but tried a full throttle run from a standstill, and frontwheels began to slip, until I lifted my gas or switched to second gear, and than the some same in second gear (also wheelspin for some time).
This was on a WET road...
(when the wheels where slipping the rpm's where getting almost to redline because of the spinning wheels)
normal??? :?


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## John-H (Jul 13, 2005)

It does sound like it isn't working but you could have teflon tyres and with the ESP turned off you don't get traction control - the standard haldex needs slip to engage the rear - So if I tell you how to turn it off and you confirm there's no difference then that confirms it's not working, rather than there being any doubt.


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## timvgti (Mar 14, 2007)

John-H said:


> It does sound like it isn't working but you could have teflon tyres and with the ESP turned off you don't get traction control - the standard haldex needs slip to engage the rear - So if I tell you how to turn it off and you confirm there's no difference then that confirms it's not working, rather than there being any doubt.


I'll try the 'handbrake method' tomorrow to let you know!
(thought that wheelspin wasn't possible at all with haldex, but I do have a lot off wheelspin)


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## starski4578 (Aug 24, 2007)

Your describing exactly the same problem i had. At first i thought it was the tyres so i changed them to F1's but still had major wheel spin issues.

I ended up replacing the haldex controller and the wheel spin has completely been eliminated even in the wet.

First thing i would suggest is vagcom the car as the error will show up and its not to uncommon for the actual haldex to fail so i would check first before rushing out and buying the controller. The best way to test if your cars running in fwd only is to pull the fuse and see if there is a diference the difference should be night and day in wet conditions. 
Stu


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## matteeee (Mar 5, 2007)

Does the ESP work? If the ESP fails (constantly lit could tell you something)..

If the ESP fails for some reason, you will get a FWD car... So it doesnt have to be the haldex.

Check this DIY-test for the Haldex also... http://forums.audiworld.com/tt/msgs/1452481.phtml

If this doesnt give you more answers, have faultcodes read...


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## timvgti (Mar 14, 2007)

Okay, I vagcommed it, with this fault:

_Address 22 -------------------------------------------------------
Controller: 02D 900 554 B 
Component: HALDEX LSC ECC 0006
1 Fault Found:
01155 - Clutch
04-00 - Mechanical Malfunction_

So indeed, the haldex isn't working I think.
What's wrong?
:?  :?

Also wanted to check the fuse, but looking into the fusebox, I see no fuse at all in number '31', is this normal??? Shouldn't there be a fuse:


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## timvgti (Mar 14, 2007)

Okay, found out that my (1999) quattro hasn't got that fuse.
Resetted the vagcom fault today and did some new WOT runs from standstill today. Noticed that only in first gear I heard/felt some short wheelspin, but that changed to grip, so I could easily change to second gear, without any extra wheelspin.

After some of those runs I checked the AWD/Haldex module again, but no faultcodes anymore...

Think my car is a 4wd again...

Maybe there is an intermittent fault with the haldex because of the old haldex-oil???
(I haven't changed the haldex oil and maybe the old owner didn't also)


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## TTmarlin (Mar 18, 2008)

I had same problems awhile ago and i changed the Haldex oil and filter ( which was much easier than it sounds )
Reset VAGCOM

thats 5,000mls ago and still no return of the code


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## timvgti (Mar 14, 2007)

TTmarlin said:


> I had same problems awhile ago and i changed the Haldex oil and filter ( which was much easier than it sounds )
> Reset VAGCOM
> 
> thats 5,000mls ago and still no return of the code


Did you have the same vagcom fault? (01155)
And your haldex is working okay? Can you slip your front wheels in the wet?


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## TTmarlin (Mar 18, 2008)

yes i had the same VAG COM code about Haldex clutch malfunction.

front wheels, sumtimes 'skip' then i can sense something going on at the rear :roll:


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## timvgti (Mar 14, 2007)

TTmarlin said:


> yes i had the same VAG COM code about Haldex clutch malfunction.
> 
> front wheels, sumtimes 'skip' then i can sense something going on at the rear :roll:


Thanks! So changing the haldex oil 'could' solve my problem?
(I hope so)


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## auditt2000 (Mar 24, 2008)

Hi, I am having some issues with my Haldex, when you put your new fuse in number 30 what amp fuse number was?


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## elliotward (Jan 27, 2007)

sounds fun a bit of driftin


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## Wak (May 6, 2002)

allewijn said:


> Okay, I vagcommed it, with this fault:
> 
> _Address 22 -------------------------------------------------------
> Controller: 02D 900 554 B
> ...


unfortunately of the two types of fault this is the worst to get. by all means try the haldex and fluid change to fix it its worth a go!

But DONT assume its cured because the fault doesnt return, it needs certain conditions to test it.

The Haldex controller faults are easy to register because the electronics either fail, or they operate their mechanical parts and measure they work and if the dont, you'll get a Haldex controller type of failure or haldex memory fault.

The fault you have above occurs because the controller has done its job, the input from the Rear ABS rings has detected a massive difference in wheel speeds between the front and rear wheels and therefore the HALDEX DIF itself is considered non-functional with a mechanical failure!

Appreciate in most dry conditions you may get enough traction to have little difference in front and rear wheels so your fault may not return.

Ideal conditions to test ( or force ) this mechanical fault is to try and launch the car on a very wet surface to ensure you exaggerate the front wheel slip against the rear wheels to ensure the fault is cured.

if its still a problem you'd probably feel some front wheel scrabble but if not there should be minimal slip and a clean-ish take off. But try that a few times on wet ground and then check for faults.


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## timvgti (Mar 14, 2007)

Wak said:


> unfortunately of the two types of fault this is the worst to get. by all means try the haldex and fluid change to fix it its worth a go!
> 
> But DONT assume its cured because the fault doesnt return, it needs certain conditions to test it.
> 
> ...


Thanks!
I'll go to my garage to change the haldex oil and filter this week.
Hope this solves the problem.
I'll try another 'wet spin' after the oilchange and post my experiences after.
If the fault still comes back, do you think the haldex controller is knackered then?


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## Wak (May 6, 2002)

I think the haldex is knackered but the oil change may be a solution, if the garage you go to has all 4 wheel off the ground they could run the car in gear and see if the rear wheels are driven.


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## Adam RRS (May 25, 2006)

i'm gonna have a standard haldex for sale next week? If you need it?


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## timvgti (Mar 14, 2007)

Wak said:


> I think the haldex is knackered but the oil change may be a solution, if the garage you go to has all 4 wheel off the ground they could run the car in gear and see if the rear wheels are driven.


I know it is possible to take all 4 wheels off the ground in this garage, so I'll ask if they can do that.
But how does this work? Just lift all 4 wheels off the ground, start the engine, put it in first gear and look if all wheels are rolling?


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## timvgti (Mar 14, 2007)

'WAK': Do you know how to see if my haldex is working if I take al 4 wheels off the ground (in the garage)?
How to do this? Just put it in first gear? :roll:


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## Wak (May 6, 2002)

yes, the only issue may be that if it were borderline then with no load it may still be working but when on the road it may not.

this is just one test to see if its completely dead or there is some life left in it!


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## MCPaudiTT (Jan 17, 2007)

http://forums.audiworld.com/tt/msgs/1452481.phtml


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## timvgti (Mar 14, 2007)

Wak said:


> yes, the only issue may be that if it were borderline then with no load it may still be working but when on the road it may not.
> 
> this is just one test to see if its completely dead or there is some life left in it!


But I thought that if you just put it in first gear en let the wheels slowly drive/roll, the haldex system is just a fwd, and only when 'slip' is detected, the rears come into play.
So if I just put it into the garage, and take al four wheels off the ground, only the front is driven, or am I wrong?


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## Wak (May 6, 2002)

You appreciate that slip between front and rear wheels is detected by the front wheels moving and the rear wheels not moving through the abs system?

more than about 6 degrees rotational difference then the ECU tells the haldex to get the rear wheels moving! Guess what will happen when the wheels are in the air! 

its like having it on a rolling road, rollers are not connected or driven , they are driven by the car. 
The rear wheels should turn if the haldex is working on a rolling road.


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## s3_tr (Apr 5, 2008)

i have haldex problem same as yours. but difference is my haldex working sometimes. my problem started after i put spacer on my wheels. 
i don't know spacers are related with haldex problem?

i can solve my haldex problem for a while by restart my engine a few times when i'm driving it.

my esp turn off every start up.(after a few minutes).

i changed my haldex oil before 2000km. but i did't make any vagcom operation.

what can i do now?


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