Hi Paul, Front wheels on some wet grass, if front wheels spin & you don't move forward Haldex/AWD is not working.
If minimum spin & TT is pushed forward Haldex/AWD is working.
Hoggy.

 

Are you clicking next at each stage of the output test?
I didn't (because I didn't know any better :lol: ) when I first tried doing the test and it didn't do much!
Once I'd realised that you have to click next at every stage I found that the test on my car completed in the exact same way as shown in that YouTube clip.
Rather than using wet grass ( I couldn't get access to any ) I found that finding a country lane with plenty of loose gravel on its margins was an easier way to test the Haldex.

 

https://m.youtube.com/watch?v=_z-wR-xIudM

Are you clicking next at each stage of the output test?
I didn't (because I didn't know any better :lol: ) when I first tried doing the test and it didn't do much!
Once I'd realised that you have to click next at every stage I found that the test on my car completed in the exact same way as shown in that YouTube clip.
Rather than using wet grass ( I couldn't get access to any ) I found that finding a country lane with plenty of loose gravel on its margins was an easier way to test the Haldex.

.... this is the same video I found. The weird thing is that when I click on Start/Next it says "Precharge pump off" then when I click Next it just pause for about 5 minutes and then says "Output completed". So I never get to hear the pump operate or the clutch.

So I was looking for a way to validate whether the AWD is working or not. Was thinking about the loose gravel method but have just had some paintwork done ...

 

.... this is the same video I found. The weird thing is that when I click on Start/Next it says "Precharge pump off" then when I click Next it just pause for about 5 minutes and then says "Output completed". So I never get to hear the pump operate or the clutch.

So I was looking for a way to validate whether the AWD is working or not. Was thinking about the loose gravel method but have just had some paintwork done ...

Then something is not quite right. When you click 'next' it should move to the next stage and definitely make a whirring noise at 'precharge pump on'.....

You're in the UK, the land of rain To test your AWD is working properly without gravel or wet grass or snow, you just need a rainy day and some smooth bitumen road - no paint damage, no burned rubber. From rest, floor it in 1st gear like a drag racer 8)
On wet, smooth bitumen the front wheels will lose traction momentarily and if AWD is operational, you should immediately feel the rear wheels kick in and then the front will also re-gain traction. It's very brief but really obvious - you can't miss it. The first time I did it, I was surprised how quickly the AWD kicks in, after reading so many articles about how crappy the Gen 1 Haldex is [smiley=gossip.gif]

That's the quick way..... the longer, harder method is to put the car up on 4 axle stands (borrow a friend's second set) in your garage. Simply start the car, put it into 2nd gear and very slowly ease the clutch out. All 4 wheels should be turning...

 

Assuming it's a 225 try a hard launch in first gear to see how much wheel spin you get if any. Pull the haldex fuse a 5A in fuse 31 and try again. If you get wheel spin now the haldex is working.
https://wak-tt.com/fuses/fuses.htm

 

...... so I just wanted to give a quick update. VCDS still won't complete an Output Test on the AWD module. It doesn't error or anything just doesn't progress past the 'precharge pump off' test.

I then decided to take some of the advice given here. Drove the car to an area of grass bordered by gravel. Front wheels on the grass, rear on the gravel 2500 RPM and set off. Traction light flashed but car drove forward. Cloud of dust at the rear suggesting the rear wheels had been driven.

I then drove to any area that was total gravel on a slight slope. Again 2500 and set off. Another cloud of dust from the rear tyres and almost an area where the gravel had been dug into by the rear wheels.

On this basis it seems like the Haldex is working. No idea why VCDS won't do a test. There are no faults logged, I can see the voltage temperature, pump status of the Haldex and all seems fine. Just can't get VCDS to do a test.

So in conclusion I am not going to worry about it. When it rains I will take it to a car park that I know which is always really slippy and try the test again. For now I'm just going to put it down to being one of those weird things that I can't explain.

Thanks to everyone for your contributions and advice. Feel a lot better now.

Cheers,

Paul.

 

Hi Paul, Appears you have nothing to worry about, AWD appears to be fine.
Hoggy.

 

Hi Paul, Appears you have nothing to worry about, AWD appears to be fine.
Hoggy.

..... huge thanks, as ever, Hoggy for your advice. I'm once again a happy TT owner!!!!!!!