Haldex not working? MKIV R32...

[Bruno89]

I've got a MKIV R32, ive had it for almost 2 years now. I'm not entirely sure when, i know its been a while, but my haldex has stopped working. when it was in the shop they told me the only code in vag-com was something related to over-speed?

ive never really thought to notice if it was working until i drove the car from minnesota to california and due to some ice, noticed it didnt work.

im stationed in lemoore, ca. so i don't desperately need awd since its california and the desert. but seeing as in a year ill be back in minnesota i sorta need it...

but back on subject, it doesn't make any grinding noises, there's absolutely no hint that its not working. other then the obvious handling and under hard acceleration the fronts slip but the backs don't engage.

i haven't had time/resources to get under the car and check the controller, i replaced the fuse, short of putting the car in the air and checking all the connections/haldex pump, im not sure what would cause it to just not work...

any helps greatly appreciated, im hoping to have a game plan so i can tackle this issue this weekend.

[ejg3855]

start with a good vag-com scan of the haldex control.

[Bruno89]

yeah, the car was scanned when i dropped it off at the shop a few weeks back, i told them to look into the awd not working and they said the only thing was the haldex was saying something about a overspeed, otherwise nothing appeared wrong.

if anyone local to lemoore, ca can hook me up with a scan, it'd be greatly appreciated

[ejg3855]

if the fuse was blown the ECU wouldn't be able to communicate with vag-com.

Run Vag Com on block 22. I am not really concerned with what the shop said at this moment. You want help you need to give responses.

[Bruno89]

yeah, i dont get a whole lot of time off, but i dont have a available vag-com, im trying to hit some people up around, bound and determined to figure this out

[Bruno89]

alrighty, finally got a update, met up with some awesome vw guys around here and one had a vag-com cable and vcds lite, so we checked, the car has two faults, one for the a/c, and other for airbags, nothing related to the haldex.

we tried scanning the awd and it didnt do anything, it showed the top two information lines and nothing else happened, im assuming this is a sign that it isnt communicating, we are going to put it in the air tomorrow and try to check the controller out

[Bruno89]

well... i put the rear of the car in the air...

spinning the left side clockwise by hand makes the right side spin counterclockwise, the differential doesnt make any abnormal/odd noise when spinning

i looked at the haldex controller, it appears to have liquid inside of the connector...

i believe im a victim of the haldex fluid migration, so now i have no idea how to fix it... do i need to replace seals, the haldex controller, and the pump? or a whole new differential?

[Lasse6]

A little tip.

If vag com cannot communicate with the haldex controller it can be a very simple fault.

There is a eletrical connector a bit forward the haldex unit under the car, this connector often fails (water and other stuff) resulting in a FWD car, check that wiring first of all.

Most of all other faults will came up in vag com

[Bruno89]

A little tip.

If vag com cannot communicate with the haldex controller it can be a very simple fault.

There is a eletrical connector a bit forward the haldex unit under the car, this connector often fails (water and other stuff) resulting in a FWD car, check that wiring first of all.

Most of all other faults will came up in vag com

can that be fixed or does the controller need to be replaced? im about to get under and get a more thorough look at everything

[Lasse6]

The cost to fix that was less than 10 USD in parts..

If you dont have any contact with the Haldex unit check this wiring before anything else.

It´s a common fault here in europe

[Bruno89]

well, so, im still tossing up the idea of replacing the rear differential, just to make sure i fix the issue, but im going to check those wires first and look at some schematics, if those wires are shorted i can easily find out and repair them, im hoping its just the wires are saturated with fluids and thats causing them to short...

can anyone recommend anything else?
ive been told to change the controller/ pre-charge pump but at around $400 total in parts its easier to spend $200 and have the piece of mind of know it will work with a new(used)rear differential...

but on the flip-side, is there anyway i can be sure if its just those wires are shorting? will the short cause the controller to go bad, or any other damage? can i remove the controller/pre-charge pump and check them to see if its just them that are bad?

im still deployed, im currently in bahrain right now, i miss my R32 alot, and have plans to fix this issue asap when im back

thank you all for the help, i frequently browse the forums when i can/have internet access