[Black16RS]

Have had the same issue with my car for several years with extended trips to the dealer which could "not reproduce the error"

I've figured out that, in my instance, temperature isn't a factor, rather, my driveway is on a slight incline. When I pull up and park, the hill start assist engages, I pull the ebrake & shut the car off. As the car shuts off, the hill start disengages and the car will squeak back just slightly onto the ebrake (less than an inch of movement). If I hit the start button again (clutch or no clutch) the same errors present with a number of codes.

1. p08b2-00 - Neutral position sensors A/B correlation
2. u0151-00 - Lost communication with restraint control module
3. u0136-00 - Lost communication with differential control module - rear
4. u0102-00 - Lost communication with TCCM
5. u0418-00 - Invalid data received from brake system control module A

If I drive the car anywhere from a few ft to the longest has been ~1/2 mile or so, the errors will clear, AWD re-engages, and I can then change drive modes.

Car goes back to the dealer shortly for further diagnostics.

 

[Black16RS]

What work have you done to the car? My bet is that you have some bad electrical grounds.

Sadly - no major mods (Velossatech big mouth, mountune intake, mountune BPV, Rally Armour mudflaps.) There is a plethora of power goodies in my basement taunting me...but not going on until they figure this out.

This has happened since I purchased the car which was previously owned by an older gentleman with zero mods.

Dealer has "checked all connections for corrosion and re-seated. They have also done the TSBs for the exhaust valve.

A local friend has an RS (has only had the errors once) and we tried in the exact locations the same steps to reproduce. Cannot reproduce with his.

 

[Black16RS]

Anyone have a good diagram source available. The more free the better!?!

I'm leaning towards sensor(s) in the rear. I can consistently reproduce the issue with the slight (less than inch) movement as it settles into the e-brake, either backward, or when I had the back on ramps, forward.

Fingers crossed this last time is the fix as my car spends entirely too much time at the dealer (~2hrs away)

 

[Black16RS]

Thankfully the speed sensors are cheap and reasonably easy.

Check the wiring /connections and check for rust before replacing any other sensors