New steering boost mapping?

New steering boost mapping?

2015 S 85D, version 2019.16.2

I’m not sure when this started, but I recently noticed that the power steering boost program seems different.

Specifically: I have long kept my steering boost on the ‘Comfort’ setting—it’s a heavy car, I like how lighter steering makes the S feel more nimble than many lesser—albeit lighter—cars. But recently, I noticed that after tight turns below about 20 mph, the steering would no longer center itself; the boost was oddly at equilibrium with the turn. This is certainly a new feeling—I was used to letting go of the wheel and feeling it spin back to center/straight.

I’ve now set my steering boost on ‘Standard’ which seems more like that to which I was accustomed using ‘Comfort’ in the immediate past. Has anyone else felt a change in the steering boost mapping?

klufkee | 21/06/2019

I have noticed the same, '15 p90d. I was ready to think it was always like that and I was crazy but now I believe it has been since the update to 2019.16.2

Thanks for telling me about Standard mode. I'll give that a shot since I also like a lighter feel.

DanFoster1 | 21/06/2019

Update: steering boost has now become erratic on every setting—this is especially noticeable at low speeds at which more boost is required. At parking speeds, every 30º of steering wheel rotation alternates between barely any boost, and way over-boosted. I’ve performed deep reboots and powered off to no avail; I suspect a malfunction of the steering wheel position sensor and/or related components.

My mandatory New York State inspection is due anyway, so my S is headed to Tesla Service for a repair for the first time in its life. I’ll update this thread with specifics when the repair is complete.

In the meantime, parallel parking is whack: I struggle to turn the first 30º against 2500 lbs of car on two big, sticky contact patches, then the boost kicks in and spins the wheel for me as if I suddenly grew Arnold’s arms. Whatever LOL, it will soon be fixed.

PrescottRichard | 21/06/2019

That’s an odd one. I lost power steering once (along with lots of other stuff) on a 2013 S, but I had all kinds of alerts and you have had none?

Maybe something as simple as power steering fluid? Fingers crossed for you!

DanFoster1 | 22/06/2019

@PrescottRichard, thank you, no, I’ve not received alerts but I doubt the car has a diagnostic for what I’m experiencing: there’s still full power steering boost, it’s just modulating oddly at points of rotation along the steering wheel. In other words, the boost is fully functional, but likely receiving erroneous input—that’s why I believe the wheel position sensor or related components are at fault. We’ll soon see if my best guess was correct!

(Model S uses ‘Rack-assisted Electric Power Steering’ so there’s no power steering fluid.)

SbMD | 23/06/2019

Sounds like your intermediate joint in the steering column may be the cause. This can happen on any car. Call your service center. Regardless of possible cause, don’t drive it if you cannot steer safely, of course.

SbMD | 14/07/2019

@Dan - just curious if you got this figured out. Hope all is fixed.

DanFoster1 | 15/07/2019

@SbMD yes, Tesla replaced the U-joint and all is well. Good call!