Haldex fixed

[Yooj]

I noticed a month or so ago that my 4wd wasn't kicking in when needed (torque steer when slippery).

When I performed a scan, I got the V181 error, pointing towards the haldex pump.

I decided to take the pump out first and clean the strainer, as others have indicated that this fixed their V181 error.

So I purchased some haldex oil and got to work.

The strainer was a bit gunked up, so I cleaned it out and refitted the pump and refilled the oil.

Incidentally, the oil was last changed 30k miles (18 months) ago. (assuming that it was actually changed, as I got the dealership to do it). And when I emptied the oil from the haldex, it was a opaque and a really dark muddy colour.

I used vcds to test the haldex. The oil change and strainer clean hadn't fixed the error, and more importantly, in addition to V181 error, I now had N373 error.

N373 error generally points towards an error with the Haldex controller... bugger!

Having read up a bit about the controller, I disconnected the electrical connectors and removed the controller... the valve stayed in situ in the haldex, which meant that I did not lose any oil.

The controller for the haldex, is basically the brain of the haldex. Essentially, all it is, is a circuit board which controls the haldex pump and the solenoid valve for the haldex clutch. It has a cover over the circuit board, which is sealed on.

I used a knife to cut away the sealant, and removed the circuit board. It was clear that in two areas around the sealant, that the sealant had failed, and thus water had got into the controller.

When I got the cover off, it was evident that the pcb appeared to be ok, and that corrosion from water ingress was only on one of the screws holding the pcb onto the controller body.

Irrespective of that, I removed the pcb from the body by removing the five screws holding it on. Using electrical contact cleaner, I cleaned the pcb. I let it dry (about 10 mins) and refitted it. Before I refitted the cover, I sprayed pcb varnish all over the pcb. This will essentially assist with corrosion protection, should water get in again. I left it around an hour until the varnish had dried.

Next I refitted the controller cover, and resealed it. I used Loctite SI 5920 to reseal the cover. I have used this sealant before, and I found it to be superb.

So I refitted the controller once the sealant was dry and rescanned the car with vcds... V181 and N373 again... Bugger!

I decided that it 'could' be the controller, but first, before throwing money at that, I wanted to rule out the pump.

Therefore, I purchased a new pump, filter and more oil from a company in the UK that has a wealth of knowledge of haldex's.

The parts arrived this week, and I got to work swapping out the parts.

(I won't go into detail of the process, as it has been covered numerous times on the internet)

So, parts swapped out, new oil filled and car scanned with vcds - Errors - None! Yes!

Went for a drive, topped up haldex with oil, and AWD normal service has resumed!

So, the long and the short of it, is that error N373 does not always mean haldex controller failure, as it might just need the pump and filter renewing.

I also plan to pull the pump apart soon, as I have seen a service kit for the pump, which is about 1/5th of the price of a new pump.

Yooj

[jets]

Thanks for posting. I would also be interested in hearing on your efforts on installing a rebuild kit for the pump.

[Yooj]

Yep will do. What I'll probably do first, is tear down the old pump and document what I find and post that up first, as it might be a straightforward fix without the need of a service kit.

Yooj

[mazzamoore]

I had a failure of Haldex not going to 4x4 occasionally and it turned out to be a battery failure (at 6 years). I had to jump start the cart and then did a quick pull out into trafic with massive front wheel spin, These haldex pumps have a high current draw for a few seconds when it needs to go to AWD. After replacing the battery and cancelling the error codes all has been well for 12 months. P.S before realising the battery problem I changed the oil and filter (after importing it from Belgium) and noticed the filter was quite clean as was the oil.

[mazzamoore]

Here we are 6 months and 10,000Klms later (now at 108,000) and I once again have Haldex error V181 so I have ordered a pump from ebay UK at $334 landed.