No drive to rear wheels (4x4 off road)

[JohnMack]

Hi all,

 

So in answer to one question, the car is a 13 plate and had done about 38k miles when the fluid was changed.

So if their thoughts are that the oil change sorted the problem ........then 4 months later the oil has degraded to what it was like at 38k miles..........surely not?

Very interested to hear how you get on........I might like a 4x4 Yeti in years to come.

Good luck.

[sampo]

Well exactly.  I suspect if push comes to shove it will be covered as I can't really see how they can reasonably argue this to be an unrelated fault to the one reported and confirmed within warranty.  They even admitted that they were unable to diagnose why the fault originally occured as there was nothing 'obvious' wrong and they did not attempt a more thorough diagnosis given that the oil change might solve it.

[Llanigraham]

Daft as this sounds, I would be getting a battery check done. There have been reports in the past of a low resting voltage affecting the operation of the Haldex.

[dbg400]

My '12 plate Yeti also had the Haldex fluid changed at 3 years/38K miles, then failed at 46K. VCDS showed a Haldex clutch pump fault, and the dealers confirmed it on their system. Fortunately the car is covered by the extended warranty, so no quibbles about fixing it. Hope you get it sorted.

[sampo]

My '12 plate Yeti also had the Haldex fluid changed at 3 years/38K miles, then failed at 46K. VCDS showed a Haldex clutch pump fault, and the dealers confirmed it on their system. Fortunately the car is covered by the extended warranty, so no quibbles about fixing it. Hope you get it sorted.

 

So dealer has just called, they've just confirmed exactly that: Haldex clutch pump failure according to VAG-COM.  I've been told this wasn't the fault wasn't recorded previously, but I guess the pump was likely to be on the way out and probably caused the system to disable the first time.  I'm getting a 50% contribution from the dealer and Skoda, so it's only costing a couple of hundred quid.  If the bill had been thousands I'd have pushed for a bigger contribution, but life's too short to get worked up over that and it should be fixed tomorrow.

Edited 20 October, 2016 by sampo

[sampo]

Just to finish this thread off for anyone who reads in future with similar problems, the haldex pump replacement has solved the problem.  Lots of 4x4 work in Snowdonia over the weekend went without a hitch.

[Brijo]

Sounds like fun !

[dasower]

Hi guys. Having problem with 2013 Yeti. The Off Road is engaged but no drive to rear wheels, well they are not turning when the front ones are slipping.

 

Had battery problem with car not starting last week took battery off and charged up. Looking at the posts it seems the error in the VCDS is reset by fitting a replacement battery or one that is fully charged, is that right ? or do I need to get the error (if there is one in the log) reset by the dealer ?

 

Belated Happy new year to all Skodaphiles.

[ejstubbs]

The Off Road is engaged but no drive to rear wheels, well they are not turning when the front ones are slipping.

Whether or not the Off-Road button has been pressed makes zero difference to whether or not drive will be sent to the rear wheels. The Haldex is active all the time unless there is a fault like low battery voltage or failed clutch pump, as discussed further up this thread.

[Ryeman]

Battery is a great first step for all electromechanical issues when a battery gets past 3 years, particularly in winter.

[voxmagna]

I think the answer to this thread is in my post #92 here:

 

http://www.briskoda.net/forums/topic/383655-haldex-clutch-pump/page-4

 

The Haldex pump motor is checked at ignition switch on by the Haldex AWD controller (22). This will momentarily apply a short electrical pulse to the pump motor and if the correct peak current is measured the system will prove and no fault will get set. As I explained, small low voltage motors like those used for the Haldex pre -charge pump can develop intermittent brush contact and any small increase in resistance (compared to the 2.5 ohm static motor resistance) will drammatically affect the short period test current pulse causing a fail and fault code set. If the motor was actually allowed to run for a few seconds after every key on and average current measured, I think the brushes and commutator would self clean and the test would pass. This is an example of electronics design engineers misunderstanding d.c motors designed before they were born!

 

Unfortunately, once the fault occurs, the AWD system doesn't seem to come back if through some vibration, the motor comes back good - 1 shot and your AWD (4WD) becomes 2WD until a Stealer does a scan and reset! There is no dash warning of this failure lockout which is bad design and you only find out doing a gravel or mud drive, when there is no drive to the rear wheels. Too late when you are up to the axle in ****!

 

A low battery might have been a factor because the test current measured for the Haldex pump motor during initialization may have been just below the pass threshold. But my money would be on the same problem as mine - poor brush contact and the controller motor good/bad proving concept flawed.  The Stealer will probably charge up a replacement Haldex pump and oil change and you are on borrowed time until it happens again. Still, be re-assured there are probably a few Yeti 4WD (and Audis?) driving around with owners unaware they haven't got 4WD until their next service scan.

 

The Haldex clutch is mostly mechanical design but relies on some electro mechanical parts and a controller for it to activate and that is what the start up diagnostics are checking. I have seen similar problems on ABS systems where a relatively minor fault causes the checking system to lock out ABS which has to be reset after garage investigation. This is often the meaning behind the message 'Take to Garage'.

 

You are correct about the 'off road' switch. All it does is electronically modify the accelerator and torque for finer control at reduced maximum speed.  AWD is there all the time to some percentage, particularly during starting and acceleration. That's why it's called All Wheel Drive and not aka Landrover Defender 4WD.

Edited 18 January, 2017 by voxmagna

[dasower]

Well that explains a lot, I had the car to local dealer and they did diagnostics, found error message for haldex punp. Did ask about the flat battery but they said that would not be the cause of the problem.

 

They cleared the error and said to fetch vehicle back in a couple of weeks and they would see if the message is back again then if it was I would need to borrow some cash from my better half or get a spot outside M&S with my guitar and next doors dog.

 

Anyway it seems a poor set up that has no was to let you know if it is working or not, the 4 WD option was not cheap and was suppose to give the Yeti an edge against other proper 4 WD motors.

 

So I could do with a way of checking myself to look at the error messages, have found this on fleabay 

 

OBDeleven Android Audi VW Bluetooth Diagnostic Tool OBD2 VAG CAN HEX VAS VCD COM

 

Do any of you skodaphiles know if I would be able to view and possibly re set the error codes. ?

[ejstubbs]

The Torque Android app (pro version also available) is able to view and clear fault codes via a bluetooth ODBII adaptor.  The latter (an example of which you seem to have found) are cheap as chips on Amazon or the bay of E.

Edited 19 January, 2017 by ejstubbs

[voxmagna]

The Torque Android app (pro version also available) is able to view and clear fault codes via a bluetooth ODBII adaptor.  The latter (an example of which you seem to have found) are cheap as chips on Amazon or the bay of E.

 

I shall be using that App or OBDwiz  App with my OBD Scantool. However, if you get a repeat of the pump motor open circuit fault, you will be able to clear it but it will come back if the system gets the slightest sniff of an open circuit motor the next time you switch on and the controller self checks. The Stealership is only doing the simple diagnostic check and clear and hoping for the best, or that you will not notice there is no AWD! My concern is I don't need AWD most of the time but when I do really need it I won't know if it will be there or not. Keeping diagnostics in the car won't help when it's stuck with the front wheels spinning.  I hate to say this, but a whack on the pump motor, followed by a diagnostic scan and fault clear might be quicker than putting snow chains on the front wheels. If there was a cockpit warning (which they could provide with a software mod.) they might get a sudden rush of 4WD Yetis with intermittent open circuit pumps and would have to address that issue as well as the ECU fixes. Don't hold your breath, the number of 4WD Yetis sold may be too small for Skoda to address the issues.

 

The issue to take up with Skoda is why there is no cockpit warning given of Haldex transmission failure.  I would have thought failure of AWD to operate was a pretty serious fault on a supposed AWD vehicle? For now my cleaned up motor might soldier on for many uncertain miles and perhaps they think 50k is the motor service life? I might now think about adding my own electronics to monitor the pump motor current whilst I'm driving.

[dasower]

Well I had thought about finding the connection to the haldex pump or where the feed comes from and using one of the spare buttons in the dash and a led to show if it is getting power.

 

Have Elsawin so should be able to pick up a feed somewhere.

 

Probably finished with this topic now. 

[voxmagna]

That will work once the controller is happy after testing for motor current. Once it faults, there will be no voltage until the fault code is cleared . In that respect a led would be a good idea and cheaper than having OBD diagnostics permanently plugged in, because it basically tells you if the pump motor is locked out or not by the software. If anybody can suggest an easy convenient neat wiring route from the Haldex unit to the center console, that would be helpful and I would add it to MY12. I have spare switch covers next to the 'off road' switch and one of those could take a 3mm led. I'd probably use a standard led and resistor so I can adjust the brightness.

 

The loom between the pump motor and controller is short and a pain for removing the plug. Best to solder splice and heatshrink sleeve a couple of 100mm long wires to increase its length. I'm not sure what the polarity is on the pump wires? Best to put part of  the led resistor value at the motor in each wire and heatshrink over, then any accidental short to the long led wire won't take out the controller or fuse.

[voxmagna]

O.K, I think I'll do it with a cheap wireless rf remote in a potted box operating a 12v switch and no wires. Hack the remote button to stay on permanently, remove coin battery in remote and power on from the 12v pump supply via a 3.3V regulator chip.

[Yety]

On ‎20‎/‎01‎/‎2017 at 17:22, voxmagna said:

The loom between the pump motor and controller is short and a pain for removing the plug.

 

Excellent write up,  spurred me on this pm to get the car in the air for a look. I've had a Volvo filter for some time, but other things have been in the way .

 

I've cleaned off the crud around the pump body and filter cap ready to have a go tomorrow to replace the oil again, change the filter and hopefully the pump strainer.

However, although I've unclipped the visible pump supply cable there appears to be no spare cable to "pull" the pump into better view, although all I want to do is check/clean the strainer.

I guess the two little screws on the pump flange are to remove the motor cover?

 

What does unscrewing the M14 support bush bolt do - give more cable access? I can't seem to trace the cable - I guess it plugs into the controller somehow?

 

Any help gratefully received before I set to tomorrow!

[Yety]

Further to the above, all was explained in earlier posts

 

Anyway, I used a dodge found on some forums, slacken the filter bolts about halfway out, start the engine and the aluminium plate, white plastic holder and the filter pop free of the body, but still held captive.

 

First thing was the white plastic bit, different to the bit with the Volvo kit. No problem as you can use it again of course.

The filter looked ok, no debris apart from a gelatinous substance on the filter surface. This seems to be the same stuff that comes out of the fluid as "blobs" which are soft and just squish up into fluid.

Cleaned it all off and got it all back in together quiet easily.

 

Next problem was I didn't have a M14 torx - only found out under the car - M12 was my biggest

 

I used a metal syringe with a small bore plastic pipe, it has to be small to get inside the gearbox past something nearly blocking the entrance. Just fill slowly to allow the oil to drop under gravity - slow but sure.

 

I'm getting a M14 spanner from a friend, but the bit that surprised me was I used my existing Haldex fluid bottle, 300ml of which remained from a fluid change in 2015. As I was drawing the fluid up into my syringe, I could see cloudy fluid with stringy bits. I pushed it back into the bottle and decanted a bit out to have a better look. It looks strangely like the "blobs" which drain out with old fluid. The bottle was date stamped 2014, and the top sector of the 300ml seemed fine.

 

What is it, is it normal, anything to be concerned about?

 

Well done to Voxmagna - first time I've seen such a detailed service of a Gen4 Haldex on a Yeti.

 

Hope to get the pump out next, weather permitting. 

[voxmagna]

You will have to drain and refill again after refitting the pump. You will probably find more 'gloop' in the nylon pump strainer than on the filter you just took out. Read my post on the pump: Remove the cover, clean the commutator slip rings and brush holders with meths/ind. alcohol, check the motor brush lengths, clean the brush holders of any debris and lubricate them with switch cleaner.  Splice/extend the motor connector wires about 100mm and consider fitting an inboard led to tell you when the 12 V pump is active (or locked out by the Haldex controller and no 4WD).

 

The only gloopy stringy oil I've come across is chainsaw oil.

.

Edited 25 January, 2017 by voxmagna

[Yety]

1 hour ago, voxmagna said:

You will have to drain and refill again after refitting the pump. You will probably find more 'gloop' in the nylon pump strainer than on the filter you just took out. Read my post on the pump: Remove the cover, clean the commutator slip rings and brush holders with meths/ind. alcohol, check the motor brush lengths, clean the brush holders of any debris and lubricate them with switch cleaner.  Splice/extend the motor connector wires about 100mm and consider fitting an inboard led to tell you when the 12 V pump is active (or locked out by the Haldex controller and no 4WD).

 

The only gloopy stringy oil I've come across is chainsaw oil.

.

 

Yes, thanks - I've no problem dealing with the pump.

 

I'm more concerned about the fluid. I need to examine the stuff in my 2014 container more carefully. The fluid is milky, looking emulsified, and contains stringy elements which doesn't seem right. The top part which I extracted from the container was clear. I'll be looking for a thin walled transparent container to examine more closely.

I just have this feeling that this gloop might be "connected" with the "blobs" we see when draining old fluid out - possibly.  

[voxmagna]

I know Haldex fluid is supposed to be a special product at a special price, but what do we know about it? Is it actually a mineral oil or something else? One important characteristic must be its viscosity for their pumped system. Unlike a multigrade motor oil, I would expect its viscosity to be maintained constant over a wide temperature range. To prove if it's oil or not I might stick some in the freezer to see what happens. Is it hygroscopic and likely to absorb moisture when stored? If you know a helpful garage chap, they have a device for measuring water in brake fluid. I bought a fresh bottle from the Skoda stealer which was cheaper than some Fleabay sellers. At the moment mine is clear and a bit gloopy like chainsaw oil. Chainsaw oil is made thixotropic to help it stick to a rotating chain.

[Llanigraham]

COSHH sheet for Ford's Haldex Oil:

https://www.fcsdchemicalsandlubricants.com/main/msds/us177448us.pdf

 

And another:

http://www.mpmoil.nl/pdf/msds/EN/vb_mpm_50000BWH_EN.pdf

 

[Yety]

6 hours ago, Llanigraham said:

COSHH sheet for Ford's Haldex Oil:

https://www.fcsdchemicalsandlubricants.com/main/msds/us177448us.pdf

 

And another:

http://www.mpmoil.nl/pdf/msds/EN/vb_mpm_50000BWH_EN.pdf

 

 

Thanks Graham. Looks innocuous enough, usual ester stuff, not miscible in water etc.

 

Can't do much today as testing at a secret motorsport venue in S Wales

 

I poured some into a wine glass last night - looks decidedly dodgy. It's separated this morning into clearer fluid at the top, with the heavy ends showing as a whiteish layer. I'll leave today and see if I can take a pic later tonight.

[ejstubbs]

5 hours ago, Yety said:

I poured some into a wine glass last night - looks decidedly dodgy. It's separated this morning into clearer fluid at the top, with the heavy ends showing as a whiteish layer.

 

At first reading, I thought you said you'd poured some wine into a glass.  Certainly didn't sound very drinkable   I don't think I've even had a pint that looked anything like that - and I've consumed some fairly 'rustic' ales and ciders in my time...