Steering Rack Swap: Active Steering -> M3 Rack

[S54ca]

I've searched around quite a bit, but haven't been able to find any documentation on this swap.

Does anyone have info. on the parts / coding required for active steering -> M3 rack swap?

Cross referencing on realOEM shows that the following parts are very similar between M3 /1M and 135i's w/ active steering:

-Power steering pump (extremely similar shape / size except for the electrical connector used on the 135i)
-Steering Shaft (I believe this is exactly the same PN)

Coding wise, I'm wondering if the servotronic electronics on the active steering equipped 135i's can be re-purposed on the M3 rack. Otherwise, I believe the vehicle order will need to be recorded via NCS Expert.

Can anyone confirm or deny any of the above?

[S54ca]

I was able to swap the rack over without any drama. The steering shaft fits fine, and the key on the rack slots into the shaft perfectly ensuring correct alignment between the two.

The hydraulic lines also fit, but the supply line that is secured via the two rubber bushings on the front of the rack puts undue stress on the isolators. I'd recommend swapping the line for a non active steering one.

Where I'm slightly stuck now is coding. I currently have the following errors:

Active Steering light in cluster and on iDrive.
DSC error after vehicle reaches 10mph (no communication to rack).

What I've tried:

Removed $S217 (active steering) from the VO and flashed the CAS, NFRM, and JBBF2; changed all mentions of active steering in Kombi & DSC to nicht_aktiv

After all this, the AL module still appears in ISTA/D - which is puzzling.

What I'm trying next:

Remove module / fuse
Change DSC ZB# via winKFP.

Helpful feedback appreciated.

[asbrr]

May be something in this thread:


https://www.1addicts.com/forums/show...hlight=m3+rack

[S54ca]

Was able to successfully code out active steering and get rid of all DSC errors with the following procedure:

1. Change VO (remove $217); FA_write to CAS and NFRM (make sure the NCS profile being used is able to modify & write, it didn't take if the AL module is still showing in ISTA or INPA)
2. Change any mention of 'AFS' in the KOMBI man file to nicht_aktiv
3. Update DSC ZB# to the latest contained in E89 datens
4. Calibrate DSC module using ISTA/D

[slavi.yordanov]

So how does it feel? Is it worth it?

[S54ca]

Originally Posted by slavi.yordanov

So how does it feel? Is it worth it?

In my opinion, yes. My main takeaways:

-Steering effort has increased significantly at a stop and during parallel parking. I will hookup servotronic, and investigate what the valve / solenoid on the pump does later on - the weight is a bit much now at low speed.

-Rack speed around town is very similar. The M3 rack feels quicker at freeway speed and the car changes direction immediately.

-Feedback and feel is much better with the M3 rack.

[UsualSuspect]

Originally Posted by S54ca

In my opinion, yes. My main takeaways:

-Steering effort has increased significantly at a stop and during parallel parking. I will hookup servotronic, and investigate what the valve / solenoid on the pump does later on - the weight is a bit much now at low speed.

-Rack speed around town is very similar. The M3 rack feels quicker at freeway speed and the car changes direction immediately.

-Feedback and feel is much better with the M3 rack.

What about high speeds, is it more stable?