[DoZZa]

I'm trying to resolve an intermittent issue with my steering on a OG 2017 M2.

I have used ISTA to start-up the EPS. That solves the issues for a while, but after doing around 100 miles, the issues returns.

The issue is a slack feeling in the steering around the centre point, and general unsteadiness on the road. Lots of micro adjustments to the steering wheel are required to keep the car steady. Driving at speed feels very unstable.

Suspension components have been checked, alignment is fine. I replaced the inner TCA bushes a couple of months ago as the car has done just over 60k miles. I've had it since new.

I thought I was just being too sensitive, I'm a sim racer, so steering feel is everything! But after doing the EPS start-up with ISTA. The steering feels nice and tight. But the effects don't last long an the steering changes behaviour again after driving around 100 miles.

I was expecting to see the SZL ECU in ISTA to check the steering angle is being reported correctly, but it's not in the list, I also checked with another diagnostic tool from Launch that also doesn't show the SZL as being equipped.

ISTA does not complain of the SZL being missing from the ECU tree either.

I am not sure if the OG M2 has a SZL. If that's the case, where is the steering angle being measured?

If anyone has ISTA, and has recently connected to their OG M2, I'd love to know if you have a SZL ECU in the ECU tree!

Apologies of posted in the wrong section, I couldn't see a specific section for a question like this!

Cheers 😎

[DoZZa]

So I have been doing more research into this issue and have discovered that the F87 does NOT have a SZL as such.

I found the following information.
Source = https://www.bimmerfile.com/2016/02/2...ng-the-bmw-m2/

How does BMW create feel through data? The steering angle information in the F87 BMW M2 is not recorded by the Electronic Power Steering (EPS) and not via a separate sensor on the steering wheel, but is instead calculated back for the steering wheel based on the motor position angle of the EPS motor. Pretty incredible when you consider that everything you feel in your hand is a calculation.

The EPS transmits the position of the rack to the ICM control unit via FlexRay. During this process, the EPS calculates the absolute position of the rack based on the current motor position of the EPS motor and the number of complete revolutions performed by the motor starting from the zero position (straight-ahead driving position).

Taking this position as the starting point, the ICM control unit determines the wheel-specific steering angle among other things using the stored ratio parameters (rack to wheel-specific steering angle) and transmits this via FlexRay. This wheel-specific steering angle is used by the DSC among other things as a reference variable for internal control functions.

I noticed that my steering wheel isn't straight when the car is actually moving in a straight line, many pot holes where I live and I had an alignment done recently and it was obviously a bodge job! And this is what the issue is. With the steering wheel not being straight, the data that the rack is generating and sending to the ICM isn't accurate, and the ICM thinks the car is always slightly veering right when it's actually going in a straight line!

Obviously when the EPS start-up is done with either ISTA or another tool, the values learnt by the ICM are reset and everything is fine with the steering until the ICM starts to put the data together after driving for some miles with the steering wheel off centre. Then it starts to act up.

A new alignment is booked, with the intention of getting the tie rods equal and the steering wheel straight! I am hoping this new aligment and a final EPS start-up will solve the issue!

This is probably obvious to everyone else, but I wanted to share just in case anyone else is as thick as me when it comes to how things like this work 😂

[DoZZa]

[Daniel80]

Did you find the solution?

I have a similar problem with my M2 LCI , witch appeared short time after car got updated to CS Diff/Steering/DTC software.

Steering wheel is fine at low speed, and it gets firmer when switching to sport mode, but at high speeds (110km/t +) it gets unprecise and has a lose play in the center. Front feels floating and unstable.
Also my DSC keeps interfering all the time, when it shouldn`t. Like its hyper sensitive or hyperactive. DSC light blinks and its trying to correct steering when im driving trough a normal street turn going the speedlimit 60km/t.

I did check every bolt in the suspension, and have had wheel allignment at 2 different shops (They both agree that the current alignment is good). (Car sits on H&R lowering springs and spacers, but this worked fine pre-update).
I Also did EPS startup and ICM startup with Ista+ in my garage.
(Have not done DSC startup because I dont know If thats something I can do myself, and Ista+ says you should only do DCS startup when changing module).

So I still have the same problem.
And no solution.

Car was good to drive and without these problmens prior to CS update.
There was no faultcodes prior to update, and are noe faultcodes now.
(I did get some faultcodes after update, but the did not come back after EPS startup.
Amongst them was:
482656 Slip angle estimator - internal degradation due to SBS
48276E Autosar - StandardCore - Non-Volatile Memory - Integrity failed
And some errors in the Central Gateway Module

Could this happen if the software update is corrupted, or something has happened during the update?
Would a new software update maby fix the problem, or is it better to roll back to standard M2 OG software.

Originally Posted by DoZZa

I'm trying to resolve an intermittent issue with my steering on a OG 2017 M2.

I have used ISTA to start-up the EPS. That solves the issues for a while, but after doing around 100 miles, the issues returns.

The issue is a slack feeling in the steering around the centre point, and general unsteadiness on the road. Lots of micro adjustments to the steering wheel are required to keep the car steady. Driving at speed feels very unstable.

Suspension components have been checked, alignment is fine. I replaced the inner TCA bushes a couple of months ago as the car has done just over 60k miles. I've had it since new.

I thought I was just being too sensitive, I'm a sim racer, so steering feel is everything! But after doing the EPS start-up with ISTA. The steering feels nice and tight. But the effects don't last long an the steering changes behaviour again after driving around 100 miles.

I was expecting to see the SZL ECU in ISTA to check the steering angle is being reported correctly, but it's not in the list, I also checked with another diagnostic tool from Launch that also doesn't show the SZL as being equipped.

ISTA does not complain of the SZL being missing from the ECU tree either.

I am not sure if the OG M2 has a SZL. If that's the case, where is the steering angle being measured?

If anyone has ISTA, and has recently connected to their OG M2, I'd love to know if you have a SZL ECU in the ECU tree!

Apologies of posted in the wrong section, I couldn't see a specific section for a question like this!

Cheers 😎