Haldex, ABS and ESP issues

[johnlyckdal]

Hello!
Recently bought an audi a3 1.8t Quattro, with the owner saying that the 4wd was disabled, just clocked over 180 000km. He said he had pulled a fuse, and even gave me new ones to put in once I hade changed the haldex oil and filter. While pulling the fuse, I'm guessing ESP and ABS was disabled aswell, since both lights have stayed on in the dash ever since i got it almost 3 weeks ago. I got the service kit with the tool and oil and everything, plugged in the new fuse, and finally the ESP light turned off, however the ABS light stays on and the car isn't really driveable. I'm crossed and don't really now what to do next, except read the codes which I'm doing tomorrow.

The previous owner said he had bought the car, had it checked at the car check place, and then lat it sat for 6 months. I'm wondering if the haldex clutch pack is siezed up (which I read somewhere could be the issue), and if there is any way to fix this, either by driving the car, or replacing the system.

Before the car was driveable with fwd, and it functioned like any other car. But when I changed the oil and plugged in the fuse, it was undriveable. If i would describe it, it feels like a solid rear axle, one wheel skips when turning which makes for a very uncomfortable ride.

Any help would be much appreciated!

 

[<tuffty/>]

If it skips when the fuse is in and it doesn't with the fuse out it won't be the plates...

Its most likely the controller itself....

If... the rear end skips when you first drive the car but stops skipping after doing a few miles then its more likely to be the pre charge pump

<tuffty/>

 

[johnlyckdal]

If it skips when the fuse is in and it doesn't with the fuse out it won't be the plates...

Its most likely the controller itself....

If... the rear end skips when you first drive the car but stops skipping after doing a few miles then its more likely to be the pre charge pump

<tuffty/>

Yeah I drove it for a bit after writing this and tried to in some way unlock the discs if that was the case by doing circles in the parking lot, but nothing changed really...
And for the controller, you would need a new one or is it possible to clean and repair or something.
And for the abs light, will the light on the dash dissapear after changing the controller. Saw a video of a guy mentioning that the abs sensors tended to corrode prette easily, but surely a faulty abs sensor won't mess with the rear axle only??

I'm planning on scanning any codes in the week using som VAGcom or something program that my neighbhor had, I'll tell you if anything pops up then.

 

[thegoal007]

I am not totally sure, but aren't the sensors part of what feeds back data to the Haldex controller. Thee are a number of other components that feed the haldex controller to do its job - abs controller being one of them.
btw, the haldex controller , as far as I am aware, is not repairable.

for now drive safely without fuse - if you must drive it. When you are about to scan for errors with vagcom , clear all errors first. Make sure fuse is back in, start and drive the car a few yards to get the problem again and then scan for codes.

You may want to fix the easy/less costly issue(s) first, which is hopefully the ABS light issue and if your haldex issue persists then go on to that.

 

[johnlyckdal]

I put my car up on stands today to see if I got any power at all to the rear wheels, which I did. I found it pretty comical to find two wheels spinning, at opposite side of the car, left front wheel and right rear. I tried pulling the nr. 31 fuse and putting it back in gear, only to find the rear wheel to spin up again, which was to my suprise. Basically

I tried removing the charge pump to see if a lot of gunk had collected, but was unable to remove a certain cable that connects to the unit. However, when draining the oil from the haldex, I found it to a lot dirtier then when it went in, very thick and not transclucent anymore.

I've looked around now and found possibly three scenarios which I believe could be causing the issue och the rear wheels locking up:

1. The clutch pack is siezed and needs to be replaced, this is due to the car standing without oil in the haldex unit for a long period of time.
2. Controller is messed up, (i don't know exactly how) but could need replacing
3. Pre charge pump faulty

Also just wondering how to make the haldex unit more accesible, lots of control arm bits in the way which makes for a very uncomfortable job.
THANKS!!

 

[thegoal007]

Of your three options, as been previously mentioned it cannot be option 1.
option 3, well i think you cna test that using VCD's. It's one of the output tests. I once read you would very quickly now if the pump was not working.

..which only leaves option 2. btw, there have been many a people who found this to be the issue in the end - me being one of them!

 

[johnlyckdal]

Yeah I've done a lot of reasearch, it makes sense and all, but I'm going to remove the pump tomorrow just to check the little filter on it.
Also, something I find very confusing is how the rear wheels keep spinning even though I pulled the fuse. Isn't the entire haldex controller and system disengaged when pulling the fuse?
I'm definately ready to buy a controller since I was under the impression the car needed £600+ repair, just need to find a way to get to it, and also make sure it's the one thing needed to fix it.
I'll try to get some tests done tomorrow and post my progress.

 

[johnlyckdal]

Alright so it's been a few days, and I got something done I think. Today I went to the store to get the stupid socket needed to move the prop shaft and managed to get the pump out after a few hours, and noticed that it was actually in very good condition; clean little filter, no corrosion, and spun up nicely when 12v was applied.

I'm guessing this crosses out two things from my little list, the clutch pack and the pump, since if the plates would have corroded there would be a lot of residue on the pump, and the pump was clean so yeah.

I also removed the controller today to check if i got current through att the pins and only 6 of the 7 pins beeped when tested. Does this mean the controller i broken and needs replacement?

I read somwhere that if the ABS system is malfuncitoning, that the haldex system will mess upp aswell, is this true?

 

[thegoal007]

OK, so I am not sure about the pins and their currents, but yes I would say the ABS could have an affect becuase I am pretty sure as I previously mentioned they all feed data to the haldex controller.

Look at fixing your other alerts first, then if you still have an issue - you should be looking for a replacement haldex controller.

 

[johnlyckdal]

I got ordered a pre-owned controller yesterday without having read this, but could always just sell my "broken" one if that is the case. For the ABS system, is it even possible for a faulty ABS system to lock up the rear wheels, I mean it doesn't really make sense to me.

If the ABS system is messed up, what could be some possible problems there? I'm starting to get a feel that it's the clutch pack , based on what <tuffty/> has said in other threads. For example, the car was left without oil for a couple months, and the oil was quite dirty after I filled it and drained it.

I'll test drive it tomorrow without the controller installed, just to see what happens, and then if it acts the same it's very most likely the clutch pack I'm assuming.

 

[thegoal007]

I got ordered a pre-owned controller yesterday without having read this, but could always just sell my "broken" one if that is the case. For the ABS system, is it even possible for a faulty ABS system to lock up the rear wheels, I mean it doesn't really make sense to me.

If the ABS system is messed up, what could be some possible problems there? I'm starting to get a feel that it's the clutch pack , based on what <tuffty/> has said in other threads. For example, the car was left without oil for a couple months, and the oil was quite dirty after I filled it and drained it.

I'll test drive it tomorrow without the controller installed, just to see what happens, and then if it acts the same it's very most likely the clutch pack I'm assuming.

I can't see it being the clutch pack, I've read too many stories with your issue and not many with that being the issue.
As I think, and Tufty hinted, based on the many people with this issue it turned out to be the haldex controller. Well now you bought one and I hope its a reputable or known good source , you will soon find out.
Just be weary that because the controller is such a well known issue you dont end up buying a second hand one with the same problem!

 

[johnlyckdal]

Alright, it's been a while...

Got my Ebay haldex controller, and made sure it was of the same year and the gastets matched and everything, plugged it in, got the pump installed, and squirted in some old filtered and new oil. Went to get the car started and I can't believe it, everything worked.

Apart from my ABS system, the car seems fully functional and is finally able to put down power to the rear wheels as well. No skipping when turning wheel fully, no wierd sounds, no nothing, it just works. As a newcomer to the audi and volkswagen train I have to say that man is there a lot of information out there, couldn't possible imagine doing this without the internet. Thanks to --- thegoal007 ---- for helping me out.

I must say I was completely fooled when trying to figure out the bottom of my haldex problems at first, it felt so obvious there was something completely wrong mechanically, would've never imagined a little controller could be the cause of so much trouble.

I haven't really touched on the ABS side of things, but I'll drive the car for now, and if anything comes up, well you know where to find it. Probably won't be gone for too long...

Thanks again

 

[bokarinho]

Hello to everyone, i own a Seat Leon 20VT 4 (ARY) year 2004 with approximately 79000km and i am facing similar symptoms. During cold starts, when i pull my car out of my garage and turn the wheel in full lock, i hear a loud click sound like something engaging and then the car operates like i have lifted up the handbrake, back wheels seem to drag and show resistance in moving. Also when i take a turn in full steering lock with low speed ESP light comes on and off, front wheels start spinning a bit and there is also that drag feeling from the rear wheels. When i drive the car for some milage the symptoms vanish, no dragging from the rear wheels, no ESP lights in tight cornering and no wheel skipping.
I have changed haldex oil / filter and also changed oil in rear diff but got no diffirent results. AWD works good, and i get no errors in VCDS.
After some reading here i narrow the problem to either the haldex control unit, the pre-charge pump, ABS control unit, other sensors. But i am really not sure what among all these is the root cause of the problem. Can you share your opinions on this? Can you help me narrow the problem to find a solution? Thanks in advance.