@ Steve - Quick look on Ross Tech's Wiki fault code page -

01324 - Control Module for All Wheel Drive (J492)
01316 - ABS Control Module
00448 - Haldex Clutch Pump (V181) ~ Oddly, I can't find a specific Ross Tech Wiki page for the 00448 fault code.

00448 - Haldex Clutch Pump (V181) 011 - Open Circuit / Intermittent
00448 - Haldex Clutch Pump (V181) 002 - Lower Limit Exceeded

However I did find this while wandering through the Ross Tech Forum -

Possible Causes -
• The Pump o-ring seals can leak, filling the motor with oil which seems to dissolve the brushes ruining the motor.
• The Haldex Controller can leak (usually in wet/cold/salty/snowy etc areas), letting water in, and corroding the board.
• The connectors can also corrode in the plugs of the cable between the controller and the motor and at the controller itself.

Possible Solutions -
• Take a look at the cable and connectors on the pump and make sure they're fit for purpose; e.g. no cracks, corrosion, etc..
• Inspect the Controller for any damage, cracks, failed cover seal, etc. Verify the connectors are fit for purpose.
• Remove the pump, check the o-ring seals and pump screen and make sure the screen is not blocked.
• Remove the pump, put 12-V across the terminals to verify the pump still runs.

If the cause still remains a mystery, it might be worth contacting these guys -
Haldex Parts and ECU Repairs by Auto Fault Finder Ltd – Haldex Mail order parts and ECU repair services

Haldex ECU Testing and Repair Service – Haldex Parts and ECU Repairs by Auto Fault Finder Ltd

www.haldexrepairs.co.uk

Found this post in the Audi-Sport forum regarding the Controller - Click here.

Opened up my Haldex to a beach worth of sand and it looks to have corroded a resistor. I've cleaned it up the best I can with contact cleaner and will probably connect it back up tomorrow and see if I'm lucky and the resistor isn't dead and I got away with out sending it somewhere for the resistor to be changed. I think Audi really should have a recall or free service for the Haldex systems as they are really poorly sealed.

Put all back together (just need to seal the box again ) took it down the road. To reset everything I disconnected the battery and it seems to be working. Once it's resealed I'll give it a proper test so glad it's not broke.

 

What car is this for?
Are you sure it's a Gen 2 Haldex system?
Even build year/VIN isn't accurate. With many MQ35 platform cars, I find easiest way it just to stick nose under and take a look at the diff/filter head/pump style/shape.

 

@ Swiss
I suspect the pump as the root cause because a simultaneous failure of the controller and ABS controller seems unlikely.

@ Barr_end
My car's build year is 2006, so it's a very early Mk2. Obviously I will look underneath before going any further.

 

2006 so I assume this is a 3.2 V6 - could well be a Gen2 after all then!
Haldexspares online is the best source you can use to get replacement parts / service parts

 

@ Steve - It will be interesting to see how the o-rings and screen look once it's out. When was the last time you replaced them?

 

If you have VCDS or OBDeleven, raise the car and command the electric pump on/have someone turn it on while you're under the car. You should hear the motor activate and operate from under the car. If not take a mallet and hit it while they have activated it, sometimes you can get it to start working if you smack it a little (will still need to be replaced if this is the case but might be able to get it to come to life momentarily).

If you remove the pump, you can probe the electrical connection to see if the controller provides voltage there when commanded on.

If you can't communicate or command the pump on through the controller to begin with, the issue is likely not going to be the pump but the controller or wiring to it. If you had salt/water ingress into the controller, like seen above, could have toasted the whole thing. I think that guy got lucky in that he only had two resistors look bad on the board, but anything is possible depending on where it got hit with moisture/corrosion.

 

When I had my car in my local Audi dealer for the haldex oil/filter service, I asked them to do the strainer on the pump which they were willing to do but said the pump was seized on and that they could have a go at removal but if they broke it, it’d need a new one……I almost fell over when I got their Audicam report and quotation.

 

Well yeah the pump is not gonna be cheap through a stealer, that's for sure. I assume by seized they just mean the pump is seized in the housing not that the motor is seized/not working?

I had the same problem, it looked like I was going to have to bash on the pump housing a lot in order to get it out. In this case I opted not to do it either as I didn't want to damage it. I think the alum housing corroding there is a common occurrence, which does indeed end up seizing the pump in the housing. It can be removed but having to bash/pry/etc. on the pump/motor assembly, I can see why they say it might get damaged.

 

The motor housing is nothing more than a thin metal can protecting the motor. I wouldn't put too much stress or use the metal can for leverage.

From the picture, you can see that the pump is inserted a fair-ways into the Haldex housing. Trying to rock the pump out is likely futile.

I would try to force the pump to rotate by hitting the cast aluminum flange with a large punch and hammer, tapping a little in one direction and then back in the other. Once you get it to rotate the pump should come out easily.

If the pump refuses to budge, I'd heat the flange with a small butane / propane torch and try again. Rinse and repeat until things start moving.

 

Yeah, my issue was the pump was seized onto the housing, they said they tried but didn’t wanna risk damaging a pump which according to them was working fine. My OBDEleven scans sho no faults in that department so rather than try and bash it off and face a hefty bill, I elected to leave it in place for now. Perhaps some very gentle persuasion and maybe heat and penetrating oil would assist, but Audi certainly aren’t gonna be arsed spending time doing that and I can’t get under the car so it’s stayed on. I’ll keep a close eye on it and maybe take it to my local Indy at some point as ideally I would have liked the pump screen replaced but hey-ho, there ya go..…

 

Thanks for all the input. I had a look underneath, and both the Haldex pump and controller look to be in good physical condition.
I used OBDeleven's Output Test, and could hear the pump running, and the function to operate the clutch worked too. So I guess that my Haldex is working!
I'll investigate further tomorrow. I broke my left arm badly last year, and still haven't fully recovered my strength and mobility, so I'm taking it gently.

 

I now think that hitting the pump with OBDeleven may have the same effect as hitting it with a hammer -- knocks a dying pump back into life temporarily. I tried it again the next day and the pump did not run. When I started the engine, the errors came back.
What I think I'll have to do is replace the pump, filters and oil.

 

I now think that hitting the pump with OBDeleven may have the same effect as hitting it with a hammer -- knocks a dying pump back into life temporarily.

I believe the Haldex pump motor is brushed. Once the brushes get worn down commanding the motor to start electrically is not enough to get things moving.

Tapping the motor gently with a hammer while power is applied 'sometimes' will bump the armature enough to start it rotating again.

Obviously beating on the pump is not a fix, but if it works you know your pump needs rebuilding / replacement.

 

 

What happens when oil gets inside the Haldex pump - "...oil dissolved the glue holding the magnets to the can and it was game over."

Found the problem with my Haldex, it's the pump.

I have been reading a lot of posts online over the past few days to try to diagnose AWD becoming FWD on my 2001 Audi TT225. It seems the system fails for any number of reasons. I don't think my failure was unique but I didn't run across it in my search. I finally decided to change the Haldex...

www.vwvortex.com

And for anyone who wants to give repairing the pump a go, here's a post which includes a link for the replacement parts kit you'll need -

Haldex pump repair guide

Hi guys, I managed to repair a faulty haldex pump (gen 1) but this can also work on gen 2 and 3 i believe. After i noticed the read end being dragged and front wheels spinning on wet asphalt i used the vcds to diagnose the haldex pump and it didnt turn on. So i removed it and saw this: The...

www.audi-sport.net

If you want a bit more information about what's inside the Haldex Pump and how to repair it, this YouTube video goes into great detail. The video is in Polish but it's easy enough to follow along.

 

Mine did come back to life briefly. I could hear it whirring away, and it was able to pressurize the system enough to operate the Haldex clutch, but the next day it was not responding.

 

Returning to this thread for advice.
I have had the Haldex pump replaced, new filter, new fluid. When I use OBDeleven's output test function, I can hear the pump running.
However, the "Pump Faulty" error won't go away.

I was sure it was the old pump at fault, because I was able to get it to come back to life briefly by tapping it.

When tested, OBDeleven says the pump pressure is 2 bar. Is that plausible?

 

Usually if a fault won't clear after a part replacement, it means there's an Adaptation or Basic Setting required.

 

Found this over on the Ross Tech Forum for a 2016 Yeti AWD with a Gen5 Haldex, so there may be something similar for the Gen2 and Gen4 -

The fix was (using VCDS of course)

Start the engine.

1. Open Controller 22 - AWD
2. Open Basic Settings - 04
3. In Basic Settings use the drop down selection box to select "MAS02928 - Pump Motor"
4. Hit "Go" and let it run. Took a minute or so, during which time I could hear the Haldex pump cycling up and down and relearning its function.

After a while the Pump Basic Setting function "Finished Correctly", and everything started to work properly.

If still in doubt, it might be worth an email or call to Matt at www.haldexrepairs.co.uk.

 

With the OBDeleven, there is an Output Test option. It has steps which you page through: pump on, clutch closed, clutch open, pump off. I could hear the pump running. I didn't keep it going for "a minute or so" though. I'll try that now.

When the old pump failed, I noticed it was easy to spin the front wheels, even on a dry road. That doesn't seem to be happening now.

I emailed the haldexrepairs address to ask if they had had any dealings with garages near me, but didn't get a reply.

 

Just to finalize this thread if anyone came upon by searching for their own problem: it wasn't the pump.

Even though the fluid, filter and pump filter were completely black, changing them did not resolve the problem. I was misled by the observation that the pump could be started from OBDeleven sometimes. I thought that must mean that the motor bushes had very nearly failed, which is a common problem.

The real issue turned out to be the control module. I removed it and sent it, Special Delivery, to haldexrepairs.co.uk on Monday. Early on Tuesday afternoon, I got a very friendly call. The unit was faulty. Not only that, they had seen it before, years ago, perhaps 2015 or so. Back then, they didn't have the same facilities, and can do a better job now. On Wednesday morning, it came back, Special Delivery, I fitted it and all was well.

Apparently the PCB fault meant that the control unit could no longer tell if the pump was running, even if it was. That might account for the intermittent running.

I might put the old pump up for sale cheaply as "runs when 12V applied, but otherwise untested".

 

@ Steve - Was there any indication of why the Control Module failed? Corrosion, physical damage to the unit, etc.?

 

Corrosion on the PCB causing damage to some components.

 

And OBDeleven didn't report any fault codes attributed to the Control Module...??

 

It did, see first post. Confusingly, fault 1324 is emitted by the ABS computer, not the 4WD one. I just jumped to the conclusion that it was the pump at fault because "0448 - Haldex clutch pump Faulty" seemed like the most unequivocal of the three codes.

The situation in reality was that 1324 was the only "actual" fault, while the other two, 1316, brake control module and 0448, Haldex pump, were side effects.

 

I think gen 2 ran from 2006 to 2010 the gen 4 system pump runs all the time were as the gen 2 doesn’t.

 

Okay, so this one...