All-wheel-drive system: 00448 - Haldex Clutch Pump (V181)

 

This has showed up in a recent scan of my Yeti, run after a number of TCS-triggering, front tyre scrabbling moments on greasy roads made me think that something might be amiss.

 

The car is going in for a service later this week and I'm in a bit of a quandary about what's best to do.  They will surely spot the error when they do the diagnostic scan, but I'm not sure what they'll say needs to be done about it.  From reports on here the "official" remedies range from replacing the clutch pump (£££) to simply changing the Haldex oil (fewer £££).  However it appears that none of the "official" remedies involve cleaning or replacing the Haldex oil filter, since VAG appear to refuse to acknowledge its existence.  As far as I can make out from other discussions on this topic, if nothing is done to the filter then any other remedial action is likely to be of only short-term benefit at best.

 

I'm not keen on having an argument with the dealership about it: from past experience they seem to be utterly convinced of the infallibility of VAG in all matters, and highly dismissive of any other sources of information not matter how strong the supporting evidence.  (Basically, I think they just put all their techs through the VAG courses and neither ask nor expect anything more from them than that.)  I'm already not looking forward to telling them that they must not apply "the fix".

 

I'd be tempted to tell the dealer not to do anything about the Haldex fault, and that I'll get it fixed elsewhere.  Trouble is, I don't know any dealers or VAG (or even Haldex) specialists in the Edinburgh area or nearby who might be persuaded to do a proper job of fixing the problem.

 

I have no intention of getting underneath the car to attempt any remedial work myself.

 

I'm open to any helpful suggestions, ideas or thoughts from forumites!

Maybe you can get a proper diagnosis and repair here, all the gear, and the knowledge & skills.

http://autohausedinburgh.co.uk 

Thanks, I'll check them out!

 

Update: hmm...the web site doesn't seem to be working 

Edited 23 October, 20178 yr by ejstubbs

I see that, hope they are still there.

0131 448 0006

32 Dryden Road

Loanhead

EH20 9LZ 

Edited 23 October, 20178 yr by Headinawayoffski

I had the same issue on mine last year with the front wheels scrambling think it was a problem with the Haldex switch,luckily it was done under warranty a week before it ran out,but I don’t think it’s a big job to replace/ repair and somebody has posted somewhere how to repair as they can be prone to water getting in.best of luck ej

Edited 23 October, 20178 yr by Sad555

Thanks offski, I'll try giving them a ring and see if they are (a) still there and (b) able to help.

FWIW, the Haldex oil was changed three years ago at ~25,000 miles.  Current mileage is ~39,000 (my use of the car has declined a lot since I no longer have to use it for work).

 

The autohaus web site is working again this morning.  I've spoken to them and arranged for them to have a look at the car next week.  Unfortunately it's unlikely to be in time to get it fixed before my trip to Northumberland the following weekend so I'll be stuck with FWD  

Edited 24 October, 20178 yr by ejstubbs

Had same fault on mine. Haldex oil was like treacle even though it was "changed" 20k before. New pump and oil, filter cleaned job done for about £360, nowhere near you sorry.

These people can supply new filters if needed

https://www.haldexrepairs.co.uk

Thanks, that's the sort of number I'm braced to pay but I'll only do it if the filter gets cleaned/replaced.  Since VAG seems to deny the existence of the filter (per the web site you linked to, and other sources) I doubt my strictly-by-the-book dealer would do it, hence why I'm looking for an independent who's prepared to exercise some discretion.

 

Was it a dealer that did yours?

No, I'm very wary of dealers, mine was done by Unit18 in Milton Keynes.

I suspect it's because the filter is not shown on their maintenance schedule.

But that does not say much for the factory training the technicians are supposed to have had.

Curiouser and curiouser...

 

The Yeti went in for its service and MoT today.  Before driving it to the dealer I sat on the drive at home with the engine running and used Carista to verify that the Haldex error was still present.  In a "nothing ventured" moment, I then cleared the error code before setting off.

 

The roads were dry this morning so no TCS.  More intriguingly, I did think that I detected the wee "shunt" from the back end a couple of times when pulling out of a T-junction.  It has previously been hypothesised on this forum (here or here) that this phenomenon is due to the Haldex always being engaged (ie providing drive to the rear wheels) when pulling away from rest.  I think I noticed it specifically because it has been absent for a while.  If that's the case then it would seem to suggest that the Haldex was operating during the journey.

 

IIRC I've read elsewhere (here, in fact) that the error can be triggered when the ECU gives the Haldex clutch pump a quick 'blip' of power during the start-up diagnostic sequence.  If the pump is gunged up then the response to the power 'blip' makes the ECU think that the pump is u/s, so it declares the whole Haldex unit as non-functional and you only get FWD.  My hypothesis is that, by clearing the error with the engine running ie after the start-up diagnostic has been run, the ECU then thinks that the Haldex is OK and runs the car in 4x4 mode.  What that might be doing to the clutch pump is perhaps best not thought about for too long...

 

So anyway, I left the car at the dealer and headed off to work, fully expecting to get a 'bad news' call later in the day.  However, when the service manager did call he had nothing more to report than an advisory note about signs of corrosion on the brake discs.  Service complete, MoT passed, car ready to drive away! (And no emissions fix applied.)

 

I assume they must have run a diagnostic scan on the car as part of the service.  I'm hoping that the Haldex error simply didn't show up when they did the scan*.  I'll check it again with Carista after I pick it up this evening.

 

I'll probably still take the car to Autohaus next week anyway: there's a limit to what can usefully be achieved using an ODBII dongle and mobile phone.

 

* A colleague of mine with whom I discussed this has a less charitable theory: that they saw the error and decided - possibly based on their past history with me - that it was simpler to keep schtumm!  I find that a little convoluted and unlikely TBH.

It has been run on the brake tester for the MOT.

It would have been Simply Clever to have made the Technician doing the service aware of the issues.

Do you know that the Diagnostic check was carried out for the service and a check for fault codes done?

Well well...

 

I did an ECU scan with Carista when I picked the car up - ignition on but engine not running - and still no error showing.  So I'm happy to accept that the dealer will have seen no error.  (The job sheet they gave me does list vehicle system test as the first item, and it's been ticked off.)

 

In the absence of damp, greasy roads there's a tight, uphill, slightly off-camber left-hander on the route I took home, departing from a set of traffic lights.  I gave it a good helping of right foot going round there and the damn thing stuck to the road like the proverbial ess aitch one tee to a blanket - not a glimmer of a sign of understeer, FWD scrabbling or TCS lights.  In the circumstances it was the best test I could manage, but the way the thing hared away up the hill certainly left me pretty convinced that the Haldex is working again.

 

I'm now fairly satisfied in my mind that clearing the fault code with the engine running bypassed the ignition-on diagnostic check that voxmagna talks about in some of his later posts in this thread, and allowed the clutch pump to get the 'kick' it needed to overcome whatever was causing it to be detected as open circuit.  Having been allowed to run for a while, the pump then behaved itself when subsequent ignition-on diagnostic cycles were run.

 

Either that, or it "fixed itself" - but as we all know, that doesn't happen:

 

 

 

So, it's nice to have 4x4 again for now, but I doubt that this 'fix' will be permanent.  Trouble is, it doesn't look like any fix is likely to be truly permanent.  Even if I do get the current pump either refurbished or replaced, without a sensor to detect when the pump is playing up it'll basically be down to waiting for the seat of my pants - or the TCS - to detect when the Haldex isn't operating, and seeing if the engine-on fault reset trick works again.

 

My plan now is to monitor the car's behaviour over this coming weekend, and run another scan on Sunday evening.  If it's still OK by then, then I'll probably postpone the visit to Autohaus until after my trip to Norfumbleland.  (Apart from anything else, other things have arisen which now mean that the appointment I have for Thursday next week is no longer particularly convenient.)

Do you not have the equipment to get under the car and have a look at the Haldex yourself? You may find nothing but my first step with problems is to look for anything obvious. unplug the connector if you can and check for water ingress or corrosion, signs of oil leaks etc. etc.

Nope, and I don't intend to go down that route (see my OP).  If I started 'looking for anything obvious' I'd very likely end up fixing it.  I don't doubt my own capabilities to do that, given patience and time, but while I have a reasonable amount of patience I have other things I'd rather spend my time on.  There are other people I can pay to work on the car.  Many of the other things competing for my time I can only do myself - for example, I can't pay someone else to go for a nice country walk with my wife (at least, not if I want her to continue to be my wife!)