hi, Having a similar but related problem on my 4.6is, spent about 30 hours troubleshooting and diagnostics but I can't pin point a mechanical vs a electronic error and can't find what's causing the code and failsafe program.
00008D IKE: EGS signal line disturbed
https://xoutpost.com/bmw-sav-forums/...-replaced.html
What is worse, we have about 20 different threads of this error code on various BMW forums, across several languages and wait for it... spent many hours trying to find and search this code. i haven't seen any shred of proof of a definite cause, explanation, and solution.
not one owner came back and reported the exact cause and what they did to fix it... they ended up by changing a lot of parts until something worked but they didn't know what it was. ?
one guy said weak battery or alternator output. if your EGS module sees less than 10 volts on crank it can cause the code. but in my case, i pinned the input voltage right at the module and my cranking minimum was 11.8 volts or higher.