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by phkahler 1457 days ago
A lot of the complexity here is because the gear selector is considered a safety-critical part. They may also consider LED indicators on it as safety-critical information to the driver. Those two things - is the transmission receiving the real intent of the driver, and is the driver being told the actual state of the system - are just the top level. Security is also starting to be a concern, though I think there is room for debate about how far they need to go with that. It's common to have all drivetrain components on a dedicated CAN bus with a gateway between it and other stuff. Your infotainment system is not going to put the car in Park regardless of what you run on it.
2 comments

Yup. Bad Things can happen:

https://money.cnn.com/2016/06/20/autos/jeep-recall-anton-yel...

I absolutely hate stateless switches on automotive stuff. Why can't I tell that my turn signal is on by 'feel'? Why do I have to rely on a (too quiet) clicking, or a (too hidden) indicator light?

I have an E70 X5 with the "new style" transmission selector, as well as a Tesla 3 that replicates it on the right side of the column. Thankfully most cars seem to have stuck with the "forward = reverse", "Back=drive" convention; confusing as it sounds, at least it replicates a move from neutral on an automatic with a traditional PRNDL lever.

Both cars also have stateless signals. The E90 and newer BMWs seem to have indicator clicks that are almost inaudible, and in almost every car I drive, the indicator lights are hidden behind the steering wheel, so you never know if the indicator has cancelled or not. On my "bad old world" BMW, at least you can feel the lever click down when it cancels.

The Tesla also has a stateless signal switch, but it doesn't give me the same issues. I think the audible "click" is a lot more distinctive or something. Alas, the green flashy light is way over in the middle of the car instead of conveniently hidden behind the rim of the steering wheel.

As an aside, I was able to change the audible level of the turn signals on my 2020 Toyota with their Techstream software (from the usual shady sources) and a Tactrix cable I originally bought for flashing my Subaru ECU. Maybe you can do the same for your vehicles with their dedicated software.
>> Why can't I tell that my turn signal is on by 'feel'?

I once had a ford rental car with turn signals that made me actively avoid using them. They felt OK, but the clicking of the relay was fake, a recorded sound. All seemed good until you cancelled the indicator. The computer sometimes kept playing the fake clicking sound. It kept clicking for a full click cycle every time you cancelled the indicator mid-click. It was only a fraction of a second, a full second at most, but I always thought that I had failed to cancel the indicator. It was both the smallest and most annoying problem I've ever had with a car.

2nd most annoying: Driving a US-made care in a country using the metric system. The cruise control is incapable of being adjusted a single kph, instead the minimum change is some number of mph. So you are stuck doing either 99 or 101, but never exactly 100 kph. The source of the problem is confirmed where the cruise control can be set to 80 kph, which is almost exactly 50mph. I venture that no BMW has ever had this problem.

In the pre-digital days I had a 92 BMW that seemed to have the reverse "problem" - pushing "up" or "down" on the cruise control settings wouldn't move you up or down a whole mile per hour, but seemed to operate in KMH - it would move something like 0.6 or 0.7 miles. (There was no direct digital readout, but it had a "average speed" trip computer that I remember resetting after some changes after noticing it seemed to move less than 1mph on the speedometer.)
Fortunately, G20 onwards have returned to a mechanically latching turning signal stalk design.

Unfortunately, ZN8/ZD8 Toyota GR86 / Subaru BRZ (the new ones!) have regressed to the dreaded mechanically momentary (non-latching) turning signal stalk design.

Noooooo! I have been following the new GR86s for a while. Hearing this makes me actually reconsider whether I really want one.
I owned a 325xi e91 and didn't experience any turn signal problems, same for my current 420i F36. Lot of German cars (VW, Audi etc) have a two stage turn signal. A light bump will do 4 or so signals and automatically stops if you move the stalk all the way it wil stay there until you move it back.

to me the sound is loud enough to hear it but not so loud it is annoying

The E90 and newer BMWs seem to have indicator clicks that are almost inaudible

That's very odd, given how much emphasis they have (or used to?) about road-feel and other forms of feedback while driving, and BMW's slogan is "the ultimate driving machine".

BMW has lost much of its driving mojo in the last decade. The quest for more customers has eroded a lot of the car's character.
e91 was a very nice car to drive the f36 is the first car that I modified because it didn't driver that well. changed the suspensions and now drivers in some ways nearly as good as the e91 and in other ways better
I recall driving a borrowed Mercedes in early 2020, the car was maybe two years old, two door coupe, nice but not super sporty, automatic. As is my habit, one of the first things I did was put it in to manually shifted mode. I found with acceleration and braking, coupled with the inertia of the gear knob, gears could be shifted inadvertently. Insult to injury, that inadvertent shift could be enough to trigger a second shift, resulting in some extremely unpredictable vehicle dynamics. A stronger set of centring springs would have been all that was required to easily filter the noise from driver intent.