S3 Haldex error 65535 internal control module memory error?

[merlin2002]

Hi guys
Ive been playing with vag-com, and I have a fault with the Haldex controller, the error codes is

65535- Internal Control Module memory error

Ive checked my Haldex Fuse, which is fine
I have no check lights on the dash
the harness conectors are clean and free from rust
I can check function of handbrake and footbrake via Haldex measure block 001
also checked Haldex Power supply and clutch oil temp via Haldex measure block 002
Also checked that ABS and Haldex are comunicating via Haldex measure block 125
ALL THIS WAS DONE IN VAG-COM

I put the S3 up on axle stands
1)pulled handbrake
2)Disengage clutch, started engine
3)Put gearbox in to second
4)Let engine idle
5)engage clutch

The car Stalled Which I belive is how it should be

now the other test I done was as follows

1)disengage handbrake
2)disengage Clutch
3)Started Engine
4)Popped it in to 2nd gear
5)let engine Idle
6)engage clutch

Now this is when Im wondering if I have a fault or not, all wheels spin and and some times only 1 rear, but they start spinning all at once not after the front has started, If I apply the Handbrake the rear wheels stop and the fronts continue to spin.

Ive tried to clear the error code, but it will come back or will say No DTC detected or error in comunication with module, then the error will come back!

Anyone have any knowledge on this, as im a little lost? It appears to work correctly, however maybe the rear wheels shouldnt start turning as soon as clutch is released?

please help me lol Im paronoid

Thanks
Rob

[towcestervag]

most faults on haldex controllers are the controller itself
ive repaced many over the years
bit fidly but ok

[msmith4000]

Hi I'm not an audi or car expert (hence I visit here :-p) but I am a computer expert. 65535 is a special number in computer terms (65536 is the maximum value that can be stored in 2 bytes of memory (16 bit or 2 power of 16 = 65536 minus 1 bit for the pos/neg sign = 65535) so this error number I think likely is not a true error number due to the firmware chip being corrupted in places.

The computer is trying to tell you what the problem is. VAG-COM if i;m not mistaken can change or clear settings / stored values held in the haldex firmware memory therefore the VAG-COM software must be writing to the memory chip. Now memory is very reliable so chances are there is nothing wrong with your Haldex control module. When there is something wrong the computer tries to tell us what is wrong but usually is unhelpfully vague.

Computers always do various checksums on data to make sure it is not corrupted. It is highly unlikely that there is anything wrong with the memory chip itself so therefore the memory error most likely was caused by data being written to the Haldex control module firware chip getting corrupted or even interupted before it was finished the process. Happens from time to time on PC BIOS chips.

I've never tried to the VAG-COM software so dont know how it works but try hooking up your lap top again and re-writing the firmware, perhapes there is a reset to factory defaults option, but load up the software again and see what you can do.

Please be aware of the following to preven computer data corruption especially when using serial communications such as with car Engine Management Systems.

1) Always use a good quality cable well shielded.
2) If your making the cable yourself dont make it to long a meter is plenty. Signal degrades over longer distances.
3) Make sure the terminating connectors of the data cables are in good order / undamged no frayed / exposed wires.
4) Always let the software finish its business whilst writing data then wait a couple minutes after it says it has finished to be sure any cached data is written
5) If given the option by the software to take a copy first of the old firmware / software please take that option.
6) Keep mobile phones away from computers and data cables at all times, especially if your using cheap cables.


Good luck chap hope you get it working again

[towcestervag]

you may be right?
but a new controller usually mends this fault

[merlin2002]

Well Ive got a used known good one in the post, should be here wednesday, so gona try jut plugging it in, see what error codes come up then, fingers crossed

cheers
Rob