Vag-Com & Garage kit think that they aren't connected

[marka 0]

I'm having a rough running problem with my car and have plugged in a laptop with VAG-COM software to try and help diagnose my problems. I know that its connected ok, as when I do the "test everything" option, it will get to and test OK the ABS... but if I try and just do the engine fault codes, it suggests that i don't have it plugged in!

 

Last week I took the car to my local VAG specalist and they used the gear they have and it didn't work for them either.

 

The engine is from a 95 VR6 and is in my late spec 94. The only thing that has been done to get the engine started after the swap was to add the immobiliser module and ECU. The ECU has been chipped (prior to my purchase), can that stop the fault/diag systems working?

 

Has anybody ever had a wiring problem with the OBD cables in the car and managed to fix it? Are there any other things I can try to get it to give me the fault codes (if there are any)

 

Thanks in advance,

Mark

[Supercharged 2]

It will probably be the chip, especially if it goes thru an encryption module...

 

Can you try the old ECU just to see if it will scan the engine?

[dr_mat 0]

If it's a standard VW ECU then there's no reason it shouldn't talk to VAG-COM for simple diags. It'll likely be the wiring to the OBD ports.

[Crasher 3]

The engine ECU is connected to the diagnostic socket via the immobiliser code line. If the wiring is all intact, which it must be for it to run and communicate with the immobiliser, I would suspect the immobiliser itself. It is quite common for the immobilisers to prevent communication with the ECU. Try plugging in another immobiliser of the same part number (some are interchangeable) to see if it communicates. If it does, the best thing to do is take the car and both keys to a VW dealer and have them code in an exchange immobiliser or if you can get a used unit with two matched in keys, just swap the box and the chips from the donor car to the original ignition keys. Be careful removing the chips as they are very fragile.

[marka 0]

Ok, thanks for the help so far.

 

Would it seem reasonable that if I just unplug the immobiliser that I may re-gain the ability to talk to the ECU? Obviously I'll not be able to start the car, but it may be a start!

 

Anybody got any ideas if the factory immobiliser can be removed totally? Is there a "hack" that can be done to make it redundant?

 

Thanks for the help.

 

Mark