DIY Haldex controller rebuild?

[Nate_O]

I'm in the US. Apparently there's a service in the UK that will refurb the controllers. The price seems reasonable, I just expect shipping to take a while each way which isn't the most convenient.

I'm wondering if anyone knows how exactly they bench test them and refurb them? I'm fairly handy with a soldering iron and multimeter.

I have an 07 A3, so that's the Gen 2 controller. I'm getting intermittent codes:

01324 - Control Module for All Wheel Drive (J492)
013 - Check DTC Memory - Intermittent
01073 - Clutch Pressure System
002 - Lower Limit Exceeded - Intermittent
00448 - Haldex Clutch Pump (V181)
014 - Defective - Intermittent

The pump and clutch appear to work correctly when I run an output test with VCDS. From reading about these errors, it sounds like the problem is most likely in the control module.

Thanks for any help!

 

[SootySport]

It's a Magic Box of tricks and if water has crept in, there'll be fair few components that have broken down. Best you can do is open the box and clean the cct. board and re-solder any dodgy joints then fit it back on the car for a test. You may be lucky and have cured the problem but if not you still can send the controller to someone who knows what they are doing.
Worth having a go yourself I reckon.

 

[Nate_O]

Thanks for the feedback. That's kinda what I was thinking. It looks like the PCB cover is just glued on, is that correct? I was looking at the pictures on here: http://www.autofaultfinder.com/index-9.html

Right now it's only a very intermittent fault. It's due for a Haldex fluid/filter service anyway, so maybe I'll get lucky and that'll fix it.

 

[Marek196c]

yep, it seem to be glue on all borders, however go carefully on it, and before I would rather change the oil in it, if not error causeb by not changing it and clogging the filters itself.

 

[Nate_O]

Thanks for the feedback guys. I finally got around to servicing the Haldex. The old filter was fairly dirty but the pump wasn't clogged up. Fluid looked good too, very clear with a little bit of non-ferrous sediment. It was maybe less viscous than the fresh fluid. The electrical connections were all in great shape. I didn't take the unit apart yet but nothing was obviously wrong with any of the parts, at least. I'm gonna drive it a bit and see what happens.

 

[Jps3290]

I stripped mine down after the same issue as I had already had a new pump on and all oil and filter changed. Pcb had some very minor corrosion in the board.

I used some WD Contact Cleaner and a toothbrush and cleaned both sides of the board. Resealed it and worked fine for a good few months now and at least 4k miles

 

[Nate_O]

What did you use to seal the unit back up? I thought about pulling it apart while I had it all off, but I wasn't sure what kind of adhesive to use to put it back together.

 

[Jps3290]

Black polyurethane sealent is what u need. I got pureflex from amazon.

Make sure u clean all the old dried up stuff out first. Takes a while but worth it to get a good seal.

 

[Nate_O]

Cool thanks, I'll give that a shot later this week. The fault seems to be all the time now, no longer intermittent, so it's getting kind of annoying.

 

[Jps3290]

When my fault startes i could clear the fault but it returned with in a few miles down the road.

When I took the unit off the car the sealant actually didn't look bad enough for any corrosion to get through it. In 1 corner their was a very very tiny hole and gap near the edge. When I took.it apart their wasn't anything massively obvious wrong with the board compared to photos I had seen of some. Mine had a small amount of crystallisation around some tiny capacitors. I just sprayed both sides of.pcb in contact cleaner and brushed with tooth brush. I did this at least 2 or 3 times. Contact Cleaner dries and doesn't cause any problems with the electronics.

When u reseal it leave it in the house for 3 to 4 yrs to set before putting back on the car. If its wet outside give it a little longer to set.

 

[Nate_O]

That's crazy. That sounds like a really dumb design.

I couldn't see any spots with obviously leaks, but once I find some of that glue I'll take it apart and see what I can do.

 

[Nate_O]

I lucked out and randomly found an A3 in a junkyard when I was looking for something else. I pulled a controller off for $27. I figure between the two of them I can either get one to work, or if not I can send one of them to the repair place in the UK.

 

[Marek196c]

I lucked out and randomly found an A3 in a junkyard when I was looking for something else. I pulled a controller off for $27. I figure between the two of them I can either get one to work, or if not I can send one of them to the repair place in the UK.

LooL that really cheap xD check on ebay.co.uk for prices xD you will be like "really?!"

 

[Nate_O]

Yeah that's nuts. I saw a bunch for like $400-500. That's a lot of money for something that might not even work. Especially since a new one is like $1k.

 

[SootySport]

So does your Scrappie one work?

 

[Nate_O]

Never got around to trying to the unit from the scrapyard. A moving truck hit it while it was parked and it was totaled. Ended up getting about $300 more from insurance than I paid for it, so I guess all in all it worked out.

 

[SootySport]

Never got around to trying to the unit from the scrapyard. A moving truck hit it while it was parked and it was totaled. Ended up getting about $300 more from insurance than I paid for it, so I guess all in all it worked out.

Strange the way some stories pan out