Locating and replacing VR6 abs ecu

[silverfox]

Hi,
I have been told by VW that i have a fault on my ECU and need to replace it.
i have been trying to find the part number for it...
VW say: 3A907379, every web site i have chwecked for ECU's (GSF and eurocarparts, even eBay) the number is 1HO907379C.
Does anybody know the part number i need? are they different between models? ie between GTI, VR6, etc.
Also - where is it? the manual states that a 96 VR6 has the ECU attached to the hydraulic pump, (in the engine bay) but there is a 'box' under the rear passenger side seat, that looks like an ECU to me, with the part number: 1HO927379C.
Confused 
which part number do i need, and where is the little bugger, if its under the bonnet this is a specialist job, if its under the seat i can do it myself.
Nick

[silverfox]

Anybody - somebody out there must know something about ABS boxes - getting desperate to sort this out. 

[GTI EDITION (aka LTD)]

The CURRENT FLOW DIAGRAM (VW) MANUAL  states that from Feb 95 onwards the ABS/EDL control unit is located on the left hand side of the engine compartment ( which I believe is integrated with the valve blocks etc .
Control units (ECU's) for the earlier models were located , separately from the valve block etc. either in the front right footwell or from 01.93 under the rear seat on the right .
( But I have found from experience that some times things are lost in translation when it comes to Left and Right in their manuals 

Sorry but I can't help you with the part number for the ECU but hopefully this may have thrown some light on your prob .

Oli