AWD Haldex clutch pump code.

prblue

Well-known member
Joined
Oct 11, 2019
Location
Poland
TDI
Golf V 2005 4motion 2.0 TDI BKD 103kW
I'm posting it here rather than car specific sub-forum, because those haldex units are used in lots of cars so hopefully it will get more exposure here.

My car is Golf mk5 4motion 2.0tdi 16v.

I've been having intermittent issue pop up usually from few minutes from starting the car to even half an hour (prior to it happening it is all fine). When it happens the yellow traction control icon gets lit on the dash and AWD gets disengaged.

Scanning with Vcds gave me:
"AWD Haldex Clutch Pump Deffective" code. Clearing the code and rescanning brings it up almost every time.

Now, I know the pump works, when it doesn't report an issue because I'm driving in very snowy conditions and I can't get up my driveway without rear wheel drive. When AWD is off and I really need it, I can usually just switch the car off and on and then it will work for a bit.

Can anyone give me any tips on this one? Should I be focusing on wiring between the AWD control module and the pump? Or should I be pulling the pump out and checking it's filter? Perhaps a haldex oil change is a good idea? (the car has 189k km on the clock and likely original haldex oil).

Are there some additional checks I can do with vcds to find out why the control module thinks the pump is defective? Does it measure pump motor current? Oil pressure? Some other sensor? I don't think it is possible to detect if the haldex clutch engages just by measuring rear wheel rotation so it must be doing one of the above.

Ill be grateful for any tips anyone can give me before I get into it so to speak.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Can you post the specific alpha-numeric DTC? We never got any TDI cars with the Haldex system here, but it should all work the same as the gasser cars that we did get. It may just be the pump motor has a bad spot in the winding, or has an intermittent connection from the controller.
 

prblue

Well-known member
Joined
Oct 11, 2019
Location
Poland
TDI
Golf V 2005 4motion 2.0 TDI BKD 103kW
Can you post the specific alpha-numeric DTC? We never got any TDI cars with the Haldex system here, but it should all work the same as the gasser cars that we did get. It may just be the pump motor has a bad spot in the winding, or has an intermittent connection from the controller.
Sure. I'm getting this:

Address 22: AWD Labels: 1K0-907-554.lbl Part No: 1K0 907 554 A Component: HALDEX 4Motion 0105 Coding: 0000001 Shop #: WSC 00000 000 00000 VCID: 2B55B2AB8A0539D507-807E
1 Fault Found: 00448 - Haldex Clutch Pump (V181) 014 - Defective

And the below:

Address 03: ABS Brakes Labels: 1K0-907-379-MK60-A.lbl Part No: 1K0 907 379 E Component: ESP ALLRAD MK60 0104 Coding: 0023170 Shop #: WSC 01279 785 00200 VCID: 3467A9D7573B662D56-8060
1 Fault Found: 01324 - Control Module for All Wheel Drive (J492) 013 - Check DTC Memory

Do you think my abs brakes fault is caused by the haldex issue? Today I'm buying haldex oil and I'll be pulling that pump out to have a look.

I think it might be what you said. I also found a video online showing that sometimes carbon dust from the motor brushes accumulate between copper sections of the motor and cause shorts.

There is a way in vcds how to measure voltage, current and pwm cycle of the pump, but I haven't found any docs describing how to find it yet. Hopefully I find it so I can compare before with after cleaning.

This is haldex gen 2 I believe.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
1 - All-wheel drive control module J492
^ Removing All Wheel Drive Control Module.
2 - Bolt
^ 6 Nm
3 - Cover
^ With vulcanized gasket
^ Always replace
4 - Haldex clutch control valve N373
^ Is calibrated with all-wheel drive control module J492
5 - Seal
^ Diameter 12 mm
^ For Haldex clutch control valve N373
^ Coat with high performance Haldex clutch oil and insert
^ Always replace
6 - Seal
^ Diameter 11 mm
^ For Haldex clutch control valve N373
^ Coat with high performance Haldex clutch oil and insert
^ Always replace
7 - Seal
^ In Haldex clutch housing
^ Coat with high performance Haldex clutch oil and insert
^ Always replace
8 - Seal
^ For pressure sensor
^ Coat with high performance Haldex clutch oil and insert
^ Always replace
9 - Pressure sensor
^ Can be reused when replacing control module
10 - Plate spring
^ In installation position, marking -arrow- must be located at top and face toward pressure sensor.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
1674732045653.png

Plate Spring Location
^ The marking -arrow- is on the convex side of the plate spring -2-.
^ The convex side with the marking -arrow- faces toward the pressure sensor -1-.
^ Marking -arrow- faces upward in installation position.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
That's all the info I have, they don't really go much into diagnostics for me, unfortunately. I looked this up for a 2008 R32, which should use the same system your car does. Hope it helps some.

Part numbers that may be of use to you:

02D-598-301 gasket set for control module (this includes what you have to remove to get the motor out)

02D-598-305 gasket set for primer pump (probably won't need this)

02D-598-574 filter kit with gaskets (wouldn't think you'd need this unless there was a bunch of trash in the unit, and if there was, there are probably bigger problems, but may be helpful)
 

prblue

Well-known member
Joined
Oct 11, 2019
Location
Poland
TDI
Golf V 2005 4motion 2.0 TDI BKD 103kW
Thank you for this. I also watched few videos how other people removed theirs.

I decided to pull out the pump without removing the haldex controller. I cracked free it's screws, but then I came here, I saw the drawing and I decided better not to mess with its seals. I managed to successfully unclip the pump plug, but manouvering that wire above the drive shaft with a huge 2in wide aluminium bracing in front and the exhaust in the way it very difficult. I've spent 2h on it and I just managed to free the haldex controller side.

There isn't enough space to put one's hands in there, so after many unsuccessful attempts to gently pry the plastic cover with two flat screwdrivers I decided to remove pumps bolts and move it partially outside. I let it rest like this for the rest of the oil to drain out and I'll be continuing...

With the removal being such a pain I wonder if installing it back will go easier.

From what I saw there is much better access in later models. For example the huge 2in wide brace that runs directly underneath the pump is gone. Also it appears there is enough space above the driveshaft one can put ones hand in there. On my mk5 4motion I can barely fit a screwdriver above the driveshaft connection disc.

Edit: I might get a heat gun and heat up the plastic clips a bit. I'm doing this in an unheated place (essentially a large tent on a concrete slab) and the temperature is freezing. Hopefully it helps.
 
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oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Well, hopefully you can maybe get it cleaned up and working again... otherwise a new controller/motor assembly will be required, and those are not inexpensive. This is why I like the longitudinal cars' Torsen system better. All mechanical, nothing as complex and fragile as this. Looks like you probably use your Haldex system more than a lot of people do, hence all the wear.

Again, they never sold these here in the "regular" cars, just the fancy stuff, and all those have engines that are generally going to explode before the Haldex would.
 

prblue

Well-known member
Joined
Oct 11, 2019
Location
Poland
TDI
Golf V 2005 4motion 2.0 TDI BKD 103kW
Well, hopefully you can maybe get it cleaned up and working again... otherwise a new controller/motor assembly will be required, and those are not inexpensive. This is why I like the longitudinal cars' Torsen system better. All mechanical, nothing as complex and fragile as this. Looks like you probably use your Haldex system more than a lot of people do, hence all the wear.

Again, they never sold these here in the "regular" cars, just the fancy stuff, and all those have engines that are generally going to explode before the Haldex would.
After cleaning it turns out the brushes are almost non existent. I'm amazed it worked at all (I plugged it into a bench psu before taking it apart and it did turn, but it had very uneven torque. I could feel it when I tried to stop it with my hand).

This little electric motor looks like it belongs in a children's toy, not in a very fancy AWD system... I guess back then in 00s brushless motors were not that popular.

I basically flushed the remnants of the brushes when cleaning with brake cleaner. I'll post some more photos once I'm done with it.

The windings look good however. I haven't measured them all, but visually there is no discoloration etc. So I decided to replace the brushes. For anyone doing the same, the size is 4x5x8mm (this is second generation haldex). I haven't got this size, but I do have bigger ones that I'm filing down to fit. The alternative would be to replace the entire pump which is not cheap so I'm willing to this first.

Also, when I drained the oil it looked very black, there was no metal shavings at all, but it crossed mind that maybe someone added moly powder to the oil (it isn't something I wold do in a wet clutch system). It turns out it was so black because of all the carbon from the brushes.

Edit: oilhammer , you mentioned replacing both the pump and the control unit. Are you thinking the code about the memory check suggests the control unit might be bad? I hope not, but who knows.
 
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prblue

Well-known member
Joined
Oct 11, 2019
Location
Poland
TDI
Golf V 2005 4motion 2.0 TDI BKD 103kW
I'm not done yet, but below are some more pictures if anyone's interested. The second photo is a "new" brush I filed to size.

It is true I do use AWD a lot. I specifically chose this car because of its 4x4 and it was half the price of a typical 4x4 SUV of a comparable age/mileage. Also fuel economy was quite important to me as well as perceived better comfort at long fast motorway driving. I have a mile or so of an unpaved road in front of my house and further 5 miles where snow is rarely plowed more than once a week in winter.













Edit: Its not looking good. Unfortunately the commutator has 2 poles missing... If I can solder a piece of copper foil there perhaps it can be restored, but it's not looking good at the moment.

Edit2: After a lot of difficulty I managed to pull the top bearing and this is how the commutator looks after 189k km.


You can see the groove the brushes made... When it was new there was no groove. I found a commutator of those exact dimensions online and I ordered it. It was only about $1.5. In general it makes you think why did they choose such an obviously inadequate dc motor.

BTW, does anyone know how often this motor is supposed to run? Looking at haldex broshure it has additional electro-mechanical valves and a hydraulic accumulator. I wouldn't be surprised if this motor run at all times topping up pressure whether AWD is engaged or not.
 
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prblue

Well-known member
Joined
Oct 11, 2019
Location
Poland
TDI
Golf V 2005 4motion 2.0 TDI BKD 103kW
Does anyone know specs of this motor? Especially the watt rating? It is 36x60 mm motor for 12v, winding wires are 0.4 or 0.5mm. I've rebuild the commutator and I replaced the brushes, but the motor appears a bit weak..

It runs and it pumps oil, but it appears to be about 10W based on current consumption. Does anyone know if this is about right?
 
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