Haldex controller question

jojo · Nov 19, 2013

Not your usual question, but would it be ok to just plug my Haldex performance controller under the car without bolting it up? No oil running through it, just want to eliminate the no comms DTC from VCDS. Shouldn't't be a problem right? The part is kind of expensive to break, so want to make sure!

hoffmanvp3 · Nov 19, 2013

Did u check the earth strap for the controller that's still bolted on?
I don't see why the pre charge pump won't come on if your not requesting it to operate via VCDS but sure one will correct me if I'm wrong

jojo · Nov 19, 2013

hoffmanvp3 said:
Did u check the earth strap for the controller that's still bolted on?
I don't see why the pre charge pump won't come on if your not requesting it to operate via VCDS but sure one will correct me if I'm wrong

My car doesn't have an earth strap as far as I know? VCDS is just showing no comms to controller, so I wanted to plug my unfitted performance one on to test the comms. Will the lack of oil effect it's operation, it's just a stepper motor that opens and close a valve right?

hoffmanvp3 · Nov 19, 2013

Not really sure tbh but there should be an earth strap iirc as that'll prob be causing ur no coms

Gops · Nov 19, 2013

It should work.. But be warned not to turn over the car.. It'll **** out oil! I'm not sure if the pre charge pump activates on ignition and oil may come out! It's not a hard job popping it back out anyhow. You using MY blue haldex?

jojo · Nov 19, 2013

Gops said:
It should work.. But be warned not to turn over the car.. It'll **** out oil! I'm not sure if the pre charge pump activates on ignition and oil may come out! It's not a hard job popping it back out anyhow. You using MY blue haldex?

I'm keeping my original Haldex in situ, just want to plug the performance one into the lead to confirm it's the lead that's faulty.

It did come off your car, but it Miiiiine! :moa:

Big Al · Nov 20, 2013

Hi Joe

The Haldex controller may work if just plugged in, but without an earth it may malfunction and damage the circuitry. Apparently many of the controllers fail in this way, as earth straps often break. Your diff unit should have an earth strap and they are easy enough to make. There should be screw posts on both the shell and trans. See this picture of my Haldex unit which I'm selling.

Al

Gops · Nov 20, 2013

Pre facelifts didn't have an earth strap

Big Al · Nov 21, 2013

Gops said:
Pre facelifts didn't have an earth strap

Really? That's weird. Maybe the loom wiring on pre-facelifts is different too, including an earth in the wiring? I can't see how the controller would operate reliably without the earth/-ve ground strap.

rupe · Nov 21, 2013

my facelift doesn't have a ground strap either and theirs no evidence of their ever having been one, I can see the stud on the floor pan where it would go, but it's covered in the factory underbody stuff.

Matt78 · Nov 21, 2013

I'm having my Y plate S3 looked at tomorrow because of this same no comms code....

Search

Search

Haldex controller question

jojo

Looking for Boost!

hoffmanvp3

Registered User

jojo

Looking for Boost!

hoffmanvp3

Registered User

Gops

Badger 5 Edition

jojo

Looking for Boost!

Big Al

Registered User

Gops

Badger 5 Edition

Big Al

Registered User

rupe

A3 TQS In Devon

Matt78

Registered User

Similar threads