Haldex pre-charge pump removal (Help)

[Greig300]

2000 facelift Audi s3 8l

After a while trying to diagnose my Haldex problems i'm going to change my Haldex pre-charge pump. Sick of intermittent FWD, burning ESP light on my dash and sometimes having rare AWD. My cars jumpy between gear changes and moving away from junctions when the ESP lights off. When the ESP light does come on its FWD... it seems to be much more free... like its not being held back. Sometimes on ignition i can hear a clicking/sucking noise from the rear end. I've Have had my car checked for errors and ive checked the cabling. When i change the pump i'll do a full haldex sevice (Oil & filter)

1 Fault Found:
01324 - Control Module for All Wheel Drive (J492)
No Communications

My main question is. What else do i need to buy when buying the pump. Any seals or bolts etc? or just a direct swap?

Going to buy this pump:

haldex generation 1 pre charge pump | eBay

Thanks

 

[jojo]

1 Fault Found:
01324 - Control Module for All Wheel Drive (J492)
No Communications

This suggests a faulty Haldex ECU, and if your 4wd is intermittent, then I'm guessing it's a classic case of corroded wires or bad earth. I'd look into those first before going for the charge pump.

 

[superkarl]

I agree with Jo.
Also, if you have vcds, check you can communicate with the haldex, and charge the pump and engage and dissengage it. I have the same fault, but can communicate with it, which is weird.
The fact you can hear the pump, like i can, suggests it still works, its just getting the wrong/dodgy signals from somewhwre.

I've done so much reading on the net about haldex issues, each with different solutions, acting on them all would mean spending A LOT of money.
I really hate the haldex, really really hate it.
Im lost personally.

 

[Greig300]

Its very frustrating... the error it shows does not really pin point a certain point.... its like it could be this could be that. I need to get it tested as yous said probably at a specalist. But i recon they will probably say its the biggest thing when it may well be a cable.

 

[Greig300]

Thing is i dont get why it works for a while... sometimes a few days then suddenly shuts off? Doubt the Haldex ECU would do that? sometimes on a straight roads the ESP light will come on with acceleration or sharp corners. longitudinal sensor? would that not have its own fault code?

 

[jojo]

Thing i dont get is it works for a while... sometimes a few days then suddenly shuts off? Doubt the Haldex ECU would do that? sometimes on a straight road just pops in with acceleration or sharp corners. longitudinal sensor? would that not have its own fault code?

A corroded wire would cause intermittent problem, as the signal is not getting to the ECU. I got the same fault code as you on my current S3, and I know it's the Haldex ECU that's faulty. Do you have the traction control light come on the dash when you pull off?

 

[superkarl]

Longitudinal sensor would have a fault code yeh,mine did, replacing it got rid of the code and gave me abs back.

Mine works when it wants, i thought the other day it broke for good, massive vibration, lost drive to rear (I thought diff had imploded)
Yet I just tried a donut in my gym carpark (empty by the way) and it feels like its working, goes round in a tight squeeling circle. But about 5 mins ago did a 4k launch from the lights and front wheels just lit up.

I'm gonna pull the fuse for it until that codes gone.
I've got to get to the bottom of it!
This weekend I'm inspecting all plugs on the unit including the pre charge pump. May even take the controller off for inspection, and diff depending how carried away i get, followed by an oil and filter change.

 

[superkarl]

A corroded wire would cause intermittent problem, as the signal is not getting to the ECU. I got the same fault code as you on my current S3, and I know it's the Haldex ECU that's faulty. Do you have the traction control light come on the dash when you pull off?

Jojo, how are you totally sure its the haldex controller? Is yours intermittent?
My esp goes off when i set off at avout 15mph, every time.
Thing is, after much internet reading, some cases its not been solved by replacing the controller.

 

[Greig300]

Well i bought the car about 7months ago now. I soon realised the ESP was not even on the dash. After asking on this forum i had a reply saying i bet the instrument cluster has been removed and the ESP light covered. I checked and yeah it was. After removing the bit of tape from the ESP light it was on every time i went over 10-15MPH. I got the car checked for faults and the code appeared. Got the car up on the ramps and removed the cable next to the backbox under a little metal shield. It was checked and cleaned it was a little scrubby but not to bad. Once cleaned out the ESP went off. But sometimes came back on after. which it still does so this has been months now. After learning more and more about the car i just know it dont feel correct. The whole rear of the car seems like its being dragged. When that ESP light comes on its FWD it seems like its lost 200KG and there is no jumpy gearchanges and it does not jump driving away from traffic lights etc. One day it was going round a roundabout and it suddenly went off and the whole car spun on the roundabout i looked and felt a right idiot. Car had plenty of grip and was doing legal speeds. Since then ive been driving like a granny in corners. Just dont trust the car.

 

[superkarl]

What's this cable next to back box undrr a shield???
This ive not seen!
Surely if you fixed it up and it worked that's your issue?

In regards to how it feels, youve got to kinda expect the loss of urgency when the power is being sent through a big prop, haldex clutcth, diff and rear wheels, its a lot of extra transmission compared to fwd, so may well be normal.

 

[Greig300]

But it jerks about... dont think AWD car should do that?

The cable is right at the rear backbox.

 

[superkarl]

Hmmmm, that is odd. Check your diff for grinding, and locking on a full lock turn. Perhaps change diff oil too.

Il have a look for that strap. I tried looking for a pic on the net for it yesterday, the infamous earth strap I'v never seen.

 

[Greig300]

I've got no idea when the oil and filter was last changed. Ive heard on full lock in reverse a clunk sometimes.

 

[superkarl]

I've.got an oil and filter to do too, no idea when mine was done, probably been neglected. Il let you know how I get on over this next week with the car off the road.

 

[jojo]

Jojo, how are you totally sure its the haldex controller? Is yours intermittent?
My esp goes off when i set off at avout 15mph, every time.
Thing is, after much internet reading, some cases its not been solved by replacing the controller.

I know, because I fitted a faulty Haldex ECU onto the car I'm selling after taking the Haldex Performance controller off it! Unfortunately in my case, the Hadex ECU is goosed on my car, not the wiring, but I no longer have time to rectify it due to a change in my work schedule, so I'm after a quick sale, so I can get my 1st S3 back on the road after 12 months off it!

 

[jojo]

Greig is right, when the Haldex is not on, the car feels like it has 200 less KGs and starts to pull through the gears! Mine drives like a LCR with short gearing with the traction control light on.