Hi All,

 

I recently had an oil change/filter clean (I hope) on my haldex.

 

I knew it was working before the service from testing with traction control off.

 

After service I didn't check immediately out of mechanical sympathy whilst it was cold and and whilst it sorted itself out with adaptions and biting points etc, but a couple of days afterwards I noticed FW spin leaving my street via an uphill, wet junction.

I've since provoked it on wet/cold roads and I'm definitely in 2WD mode.

 

A basic OBDeleven check shows no fault codes for the Haldex and there's tons of real-time data I can check that I don't really understand but suggests it is getting power (although I haven't checked the fuse, for example - fuse 9?)

 

Its back at the dealers tomorrow and I anticipate a potential argument about me taking in a working Haldex, and them returning me a serviced non-functional one...

 

I'm hoping they forgot to prime the pumps or run adaptations or something and can do that and us both be happy, rather than having to replace the <£300 part>

 

Any thoughts anyone?

 

Typically there is no need for adaptions or separate priming of the pump.

Depending on how the pump is cleaned, control unit wire is often deplugged. Possibly the wire has been left unplugged.

 

Just a wild guess and it is more likely to be something else.

Quote

 Possibly the wire has been left unplugged

 

Or they've forgotten to refill it...

 
Let's hope that they've not drained the rear diff by mistake!

 

I thought a prime/reset was required after oil change / gauze cleaning (on the latest Haldex) so it could relearn it's maximum pump power?

Edited 15 January, 20251 yr by micro

10 hours ago, micro said:

I thought a prime/reset was required after oil change / gauze cleaning (on the latest Haldex) so it could relearn it's maximum pump power?

 

I did too but after reading people not doing it I tried myself also and no problems. I guess it adapts to 'new environment' just like it has adapted to the dirty gauze.

 

Edit.

Also the official skoda service manual does not suggest adaption even after pump replacement.

Edited 15 January, 20251 yr by RattleWagon

My experience for what' it's worth.

 

If pulling out the pump to clean, the oil will drain out of the pump.

 

There is no explicit prime routine that I remember but if you fill to level of fill hole, then cycle ignition a couple of times you will find it takes another 300ml or so to properly top up.

 

You don't have to rerun the adaption but it does optimise the voltages learned.  Without running it, it stays static (as previously set at first install) and they aren't updated.

 

There's a good explanation on one of the haldex service sites. 

 

This probably doesn't solve the OPs issue and I agree with the comments made to check. Although an unplugged haldex pump would normally report a code on full scan. But should be checked. Another possibility is the pump has failed. 

A pump learn will also prove the pump works and may indicate if the PRV is faulty. It runs the pump up to the point that the pressure relief valve opens. You can hear the pump wind up and the PRV open multiple times.

 

I guess that's also a possibility - the PRV is stuck open (maybe from a small bit of debris). That's a cheaper fix.

 

See here for the pump learn on an actual unit.