My Cybertruck will not start / power on

[Gigahorse]

Not sure it need 3 redundancy system, 2 should be enough. the redundancy system only needs to bring you to a safe stop, no need to "continue driving fix later' type.

The difference is, with manual steering if you lose power steering you can still control the vehicle, with steer by wire if it goes down without redundancy you can't control it which is scary so would say sufficient redundancy is needed.

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[mark555055c]

Yea I thought the steer by wire system had 3 redundancies built in so the odds of failure was like winning 3 lotteries back to back. If that is not the case and like you said these do not have that isolation backup this could be a serious issue that would require that system to be redesigned completely.

This is correct, it's triple redundancy sensor wise, so if output of two sensors does not align, the third is there for the tie breaker. There are two motors, so double redundancy there.

The single small 48v lithium battery can operate the steering motors if the pack fails or vise versa one would to assume.

 

[BannedByTMC]

The single small 48v lithium battery can operate the steering motors if the pack fails or vise versa one would to assume.

Maybe not, steering draws a lot of power and the 48V battery may be too small.

 

[mark555055c]

Maybe not, steering draws a lot of power and the 48V battery may be too small.

I bet it could provide enough power for basic maneuverability in an emergency to come to a stop. Also, the main pack that can be split could also be an source of redundancy perhaps.

I'm confident Tesla has thought of this stuff. There is no way they taking the Jesus take the wheel approach in the event of power loss.

 

[BannedByTMC]

I'm confident Tesla has thought of this stuff. There is no way they taking the Jesus take the wheel approach in the event of power loss.

The people reporting no steering would suggest otherwise.

 

[mark555055c]

The people reporting no steering would suggest otherwise.

I think there has only been one case of this, and the details are unclear i think. Or, am i mistaken?

 

[BannedByTMC]

I bet it could provide enough power for basic maneuverability in an emergency to come to a stop.

If this is correct it's a 4ah battery, times 48V is less than 200Wh/hrs, that won't be able to do much.

https://insideevs.com/news/704749/tesla-cybertruck-low-voltage-battery-48v-4ah/

 

[mark555055c]

If this is correct it's a 4ah battery, times 48V is less than 200Wh/hrs, that won't be able to do much.

https://insideevs.com/news/704749/tesla-cybertruck-low-voltage-battery-48v-4ah/

It's indeed 4ah. So essentially a power tool battery. Seems fine for me for 5-10 seconds to come to a stop. Regardless, I'm sure Tesla has it covered, and we'll get more details and tech specs in time.

 

[BannedByTMC]

It's indeed 4ah. So essentially a power tool battery. Seems fine for me for 5-10 seconds to come to a stop.

That battery is also powering everything else in the vehicle at the same time if the DC/DC and/or main pack fail.

 

[JBee]

Lol it's funny how the conversations go full circle on every thread.

First denial, then justification, then discussion, then question, then acceptance.

One just had to read my first post on critical error thread and you'd not have to do so much mental exercises.

The reason why more than one thing is failing is because the thing that powers everything is everything but "redundant". Nothing works without power.

Now even if there was the "expected behaviour" ie pull over when error comes up, it is still a complete breakdown and failure of the vehicle so you can no longer drive.

The OP said here that the error was due to a compressor failure?

That is yet another different reason for these critical error failures.

The situation is getting worse, not better.

 

[Stuck4ger]

Wonder how many memes are being made from people seeing this on the highway

It could be a beautiful sight. My Model Y was delivered that way direct to Las Cruces from Fremont.

 

[Stuck4ger]

Probably the same thing you would have done if your old gas car just stopped. Try to pull to the side of the road and call for assistance.

You can thank me later
Sincerely
Captain Obvious

Ok but what if you got out and left your phone inside? It’s not like you could ever lock yourself out of your ICE vehicle! OMG! /s

 

[Stuck4ger]

IMO folks on this forum are way too quick to claim fatal failure modes of these new technologies without any idea of the redundancies involved. I’ve got quite a bit of fly by wire time and there is no way Tesla would certify something that couldn’t have a major power failure and still not be able to come to a safe stop. It doesn’t mean the fancy displays will stay lit or you can drive to a SC but you’ll be able to come to a safe stop.

 

[CyberGus]

the thing that powers everything is everything but "redundant".

There are at least two 48v sources

 

[Stuck4ger]

There are at least two 48v sources

I’ve seen designs where the electronic flight controls remain powered by the PMGs that are at the core of the engine-driven generators that normally provide power. And then tiny emergency batteries pick up the load in the landing flare when dead engine stops rotating the PMG. (This is a simplification of the actual design, there was even more redundancy than that.) The point is I haven’t really seen anybody with authority show all the ways the CT steering and brakes can be powered.

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