# Haldex Failure: New Haldex controller AND pre pump?



## jabjab (Jun 7, 2015)

I was hearing this shuddering noise when making tight turns in parking lots for example and took it into the shop. It was discoverd that my rear wheels were locking up only on tight turns. Tech took the fuse out for the haldex and this get rid of the noise and vibration.

So does this tell me that the haldex controller is shot or could it just be the pre pump? I find it odd because just a few months ago I had the haldex service done (filter and oil). Could the shop that did it messed something up and that maybe fried the pump? Or is this a case of juts bad timing.


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## bwdz (Jan 21, 2015)

This has been discussed so many times you need to do a search. Obviously everything is working, the pump must work if it engages the AWD and that's why it clicks on tight turns. When you pulled the fuse it stopped so it is disengaging. Everything is fine mechanically. Electronically either the controller or one of the sensors is malfunctioning. You need to run a VAG COM scan on the Haldex and on the ABS.


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## jabjab (Jun 7, 2015)

If anyone has a blue controller for sale or even oem please private message me.


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## bwdz (Jan 21, 2015)

You might find this read interesting. According to this site which specializes in rebuilding Haldex controllers, they don't offer the service for the TT gen1 controller as it is very unlikely to fail so you should do some more diagnostic rather than try to throw parts at it as your car will still likely won't be fixed but might be faster when your wallet is lighter from buying parts that did not fix it.
http://www.autofaultfinder.com/vw-audi-haldex-ecu-controller-testing-and-repair-specialist/
"This is a Generation 1 Haldex Controller, these do not often fail internally but they do suffer from pump failure which is external to the controller and can easily be replaced. Fault codes which highlight pump failure are:-
00448 – Haldex Clutch Pump (V181) 014 – Defective – Intermittent
01155 – Clutch mechanical 00-04 – Intermittent
01155 – Clutch mechanical 00-00 – Failure

They also suffer corrosion to the wiring harness under the vehicle which connects directly to the Haldex unit. Fault codes which highlight this are:-
00526 – Brake Light Switch-F 27-10 – Implausible Signal – Intermittent
01324 – Control module for ALL WHEEL DRIVE (J492) 004 – No signal/communication – intermittent.

WE DO NOT OFFER A MAIL ORDER TEST AND REPAIR SERVICE FOR THIS TYPE OF CONTROLLER
WE CAN OFFER A DRIVE IN TEST AND REPAIR SERVICE FOR THIS TYPE OF CONTROLLER"


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## All_Euro (Jul 20, 2008)

^ good bit of info - I'm waiting for a new precharge pump myself... hopefully that's all that's needed.


OP - it sounds like your haldex is engaging fine but having an issue disengaging... have you scanned for codes or checked wiring or anything? More detail will help people help you.


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