ABS Module - 3 Lights Issue

[Adas]

Hi everyone,
I'm sure this has been discussed on the forum many times before, but I was hoping for more recent updates and experiences on this issue. I have a 2003 4.6is with the dreaded intermittent "3 lights" (ABS, brake, and traction control) coming on and the resultant 'Transmission Failsafe Program' kicking in when I hit 80mph (or thereabouts). It seems to be happening more regularly than it had been (I have had this car almost 3 years and it was pretty much doing it when I got it but I've learned to live with it). It is getting more frequent now, however, and it is just annoying and I want to fix it. When I spoke to my mechanic here in CO, he said that using BMW parts it is a $2k job (gulp!) I see that there is a non-BMW part through ECS Tuning for around the $500 mark that allegedly does the same job as a new OEM BMW part.

I have also investigated various shops who rebuild the part, but I have heard that this is pretty hit and miss and my concern is that I get a part sent out and get my mechanic to install but there is no guarantee from him (obviously) and he has had issues with using these rebuilt parts on Porsches etc (from the same company) and advises against it.

Anyone out there with experience of the other part through ECS, and/or other options?

And one final question - I'm presuming that the issue described above is definitely the ABS module? My mechanic (who I trust implicitly) has assured me that it is, just wondering if there is a potential misdiagnosis here and it could be another part?