Owner experiences steering and brake failure

[CybertruckCovers]

Not sure if anyone posted this yet. This is pretty frightening if true.

https://www.yahoo.com/news/man-alar...and Phoenix-based,loaded onto a flatbed truck.

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[JBee]

Not sure if anyone posted this yet. This is pretty frightening if true.

https://www.yahoo.com/news/man-alarmed-cybertrucks-steering-brakes-180827674.html#:~:text=Tesla fan and Phoenix-based,loaded onto a flatbed truck.

There's already been 10 or so apparently.

Both scary and unnecessary. Pretty poor redundancy design, not something you want to happen whilst driving at all.

 

[cgladue]

"Disintegrating Tires" naw not a hit piece at all.

i didn't read anywhere where they were in imminent danger, did i miss something ? just the typical system failure posts we saw a few times from other members, i assume.

 

[Noblelr3]

Couldn’t be more generic and never heard of this so called “news” outlet.

 

[rbalkun]

Not sure if anyone posted this yet. This is pretty frightening if true.

https://www.yahoo.com/news/man-alar...and Phoenix-based,loaded onto a flatbed truck.

Why is it frightening…things fail on vehicles…not like he was in any danger

 

[JBee]

"Disintegrating Tires" naw not a hit piece at all.

i didn't read anywhere where they were in imminent danger, did i miss something ? just the typical system failure posts we saw a few times from other members, i assume.

Why is it frightening…things fail on vehicles…not like he was in any danger

How does the Steer by wire steering work on the Cybertruck?

It is not mechanically connected.

Also on power failure the brake booster also does not work.

This is not good by any definition of the word safe.

 

[cgladue]

How does the Steer by wire steering work on the Cybertruck?

It is not mechanically connected.

Also on power failure the brake booster also does not work.

This is not good by any definition of the word safe.

you can still steer to the side of the road its not like you loose all steering and braking. Yea not ideal but not life-threatening either.

 

[rbalkun]

How does the Steer by wire steering work on the Cybertruck?

It is not mechanically connected.

Also on power failure the brake booster also does not work.

This is not good by any definition of the word safe.

A catastrophe failure is a type of error, a lot of times when it detects a failure in redundancy and that the vehicle needs to be serviced, the vehicle still has working steering and working brakes, just American media like to spin everything off to make it negative. It’s just like how they do a huge news article saying that all Teslas are being recalled when they are just pushing an update to change a font size. There’s such a big group of people who are anti-EV and anti-Tesla that they will spin something however they can to get more social media shares and clicks.

 

[Spacenoddle]

How does the Steer by wire steering work on the Cybertruck?

It is not mechanically connected.

Also on power failure the brake booster also does not work.

This is not good by any definition of the word safe.

If we could think of it, for these critical components, There's noway Tesla enginers would overlook it, otherwise it would be open for class action lawsuits.

 

[Cyber Man]

you can still steer to the side of the road its not like you loose all steering and braking. Yea not ideal but not life-threatening either.

What if you are driving through curvy mountain roads with cliff on one side?

 

[cgladue]

What if you are driving through curvy mountain roads with cliff on one side?

Stop in the middle of the road and get as far away from the truck ad u can? I dunno. What if you are on that road and you have a tire blow out. Or a tie-rod let loose, or a wheel fall off ? There's lots of edge cases of things that can go wrong that no one thinks about and isn't probably ready to handle. And all if them are probably more likely to happen. Statistically then these issues.

 

[Chris9702L]

The story a whole bunch of nothing! Absolutely no specific except “Cybertruck bad”. Just a hit piece.
I fly a fly-by-wire airplane. It is extremely reliable and I’ve never had a computer fail.

 

[Carlos Thomas]

Too bad he didn’t provide more detail like some of the error codes. Potentially it is the same issue I had, which requires the replacement of the Low Voltage Backbone & Harness.

 

[Cyber Man]

Stop in the middle of the road and get as far away from the truck ad u can? I dunno. What if you are on that road and you have a tire blow out. Or a tie-rod let loose, or a wheel fall off ? There's lots of edge cases of things that can go wrong that no one thinks about and isn't probably ready to handle. And all if them are probably more likely to happen. Statistically then these issues.

There is no statistical data for steer by wire on trucks. All I’m saying is if this is a genuine failure of steer by wire, it’s important to look into it instead of saying the odds of getting hit by lightning are the same. No it’s not. Failure rate of Steer by wire on Cars is not known, and we cannot compare the stats with airplanes. Planes have a completely different level of quality checks.

 

[JBee]

A catastrophe failure is a type of error, a lot of times when it detects a failure in redundancy and that the vehicle needs to be serviced, the vehicle still has working steering and working brakes, just American media like to spin everything off to make it negative. It’s just like how they do a huge news article saying that all Teslas are being recalled when they are just pushing an update to change a font size. There’s such a big group of people who are anti-EV and anti-Tesla that they will spin something however they can to get more social media shares and clicks.

It's called a "Critical Failure" not Catastrophe.

You are being blinded by the fanboi propaganda, just stick to the technical items. There's pages here on the forum discussing the issue in detail.

Your statements and terminology highlight the actual issue at hand, that you believe Tesla is better than any other manufacturer and can "never" do anything wrong.

That is the opposite of reality, they are failable just like anyone else and these successive failures should not be dismissed offhand, especially seeing there are more than one type of failure that are making these happen.

The consequence of them failing whilst driving is potentially catastrophic and should not be taken lightly, regardless of how the media are reporting on them.

Further just because they "share" a similar name does not mean they have the same standards as used in FbW in aircraft.

I can call a frog a prince, but neither have similar traits or capabilities.

So to have a conversation about it requires an understanding of how it actually works, with that we can try to understand what went wrong instead of just throwing one liners on the credibility of media, which btw, I also believe don't deserve my endorsement.

From my understanding there are three sets of sensors for redundancy, and two sets of motors with their own set of sensors on the front axle. The rear axle only has one motor.

The steering wheel is connected to a rotating actuator that also provides force feedback from the steering rack sensors. The only connection between the steering wheel and actuator to the steering rack are digital signals from the sensors. The sensors on the steering send the commanded steering angle to the controller, and the controller interprets that to the corresponding steering angle on the rack according to the current vehicle velocity.

Likewise the rack sensors transfers the rack position back to the steering wheel force feedback actuator so the driver can sense which angle the wheels are pointing in, and road undulations, traction etc.

Now if the steering wheel actuator fails then you will have a very light steering wheel without the force feedback, but the redundant sensors, if still powered, can send steering angle commands to the steering rack. That would not be that bad, seeing you can still steer, but it would be like driving a remote control car.

If the Steering wheel sensors fail, you have no input in controlling the steering of the vehicle. That would normally mean the rack if still functional would go to neutral and straight ahead, and if it's not working, remaining at that angle until the steering self straightens because of the wheel toe in angle.

So the critical safety items here are that the steering wheel sensors and the steering rack motor(s) work and are powered, and they give the rack the commanded steering angle. The front rack still works with just one motor, the second one is just in case the other doesn't, but both are used all the time.

So having multiple sensors going from the steering wheel to the rack means that a whole bunch of failure modes can be overcome. You could for example lose 2 sets of steering wheel sensors, the steering wheel actuator and a rack motor, and the steering will still work.

This leaves the power supply. Without the power supply there are no sensors, actuators or rack motors, so it is super crucial that these systems always remained powered no matter what.
For that reason the PCS (Power Conversion System) on the CT uses multiple DC to DC converters from the main pack to make 48V (at least 2) and also a separate 48V battery that can provide power should the DC converters or the main pack fail. This also provides power to the other vehicle accessories, like opening the doors and running electronics and contactors to connect the main pack etc.

Many of the errors accompanying the Critical Failure are in regards to the power system failing. In some it's been the DC Converter, others the wiring harness (unplugged or damaged cables doesn't help either).

The problem here is that various different fixes for the same resulting issue is not a good sign overall, of the design choices they made. If it was one reason, we could maybe blame a single component failure, but as it is it looks like there is a wider systemic problem at play.

This could be something trivial as the wrong calculations were used to specify the connector or cable rating, or there are voltage spike from another device somewhere else along the same 48V bus that runs through the whole vehicle. There are a huge amount of local DC converters on the nodes powering locks/windows/pumps etc all of which could have a design problem that could manifest itself somewhere else in the bus. Even the audio system is running on that bus and being fed by the PCS/48V supply at some point.

The question here is how well are those critical steering and braking systems isolated from all the rest. Until now neither have been specifically located just at the steering or PCS. That means that system isn't isolated well enough and something is causing the power failures on multiple systems, which defeats the purpose of having redundant power systems.

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