Owner experiences steering and brake failure

[Spacenoddle]

They did not lose steering or brakes. They lost redundancy and the truck, because these are critical functions, instructed him to pull over and stop driving. In legacy cars, you don't need to be told to pull over because the force required to steer makes it obvious something is wrong. For the CT, a firm and scary warning plus reduction of speed is required to prevent idiots from ignoring it and continuing driving. No story here except for the fact that a couple people have experienced this which is a pretty high failure rate given the scarcity to CT's on the road.

Well said. The issue is unexpected ( or expected?) high rate of electronic failure even i still have the confident for the safety redundancy design from Tesla engineers.

Sponsored

 

[Cyber Man]

I don't mean to sound snarky but that is why the system is redundant. For example, your steering has two steering motors. Each one has three sensors. If one of those sensors loses its mind you will get a "critical failure" and told to pull over… But you still have your back up motor with three working sensors. They've been landing airplanes like this for decades

@JBee already explained everything in detail. So I don’t have anything much to add on the technicalities.

Look, I love CT to my heart, but our blind love shouldn’t make us claim that steer by wire in CT right now is as safe as it’s on an airplane. It’s not apples to apples. Probably in the future it might be but not right now. Airplanes quality check is insane. Imagine getting on a plane and seeing a panel gap or pilot screen completely going blank or wiper unable to fully wipe off rain water. Those things have happened to early CT adopters.

When owners reported rust, I disregarded that as crap; science didn’t check out for that one. This issue, I’m not so sure. I’m confident when people write software, there will be bugs. I have shipped many bugs too . Call me a bad engineer but no software is perfect. If you aim for 100% perfection, you will never ship.

Tesla needs to investigate what caused this critical failure. We don’t know if it was one motor or two motors. We are just speculating. Imagine driving in a remote windy mountain roads at night and CT steer by wire failing. Let’s not compare this with the odds of tire blowout or getting stuck my lightning. Stats cannot be compared like that. We don’t have stats for steer by wire on CT, except this particular incident. So neither math nor science checks out here. The concern here is valid, but I’m confident Tesla will investigate and root cause it.

 

[Spacenoddle]

@JBee already explained everything in details. So I don’t have anything much to add on the technicalities.

Look, I love CT to my heart, but our blind love shouldn’t make us claim that steer by wire in CT right now is as safe as it’s on an airplane. It’s not apples to apples. Probably in the future it might be but not right now. Airplanes quality check is insane. Imagine getting on a plane and seeing a panel gap or pilot screen completely going blank or wiper unable to fully wipe off rain water. Those things have happened to early CT adopters.

When owners reported rust, I disregarded that as crap; science didn’t check out for that one. This issue, I’m not so sure. I’m confident when people write software, there will be bugs. I have shipped many bugs too . Call me a bad engineer but no software is perfect. If you aim for 100% perfection, you will never ship.

Tesla needs to investigate what caused this critical failure. We don’t know if it was one motor or two motors. We are just speculating. Imagine driving in a remote windy mountain roads at night and CT steer by wire failing. Let’s not compare this with the odds of tire blowout or getting stuck my lightning. Stats cannot be compared like that. We don’t have stats for steer by wire on CT, except this particular incident. So neither math nor science checks out here. The concern here is valid, but I’m confident Tesla will investigate and root cause it.

i am not too much worry about the safety concern becaus no one reported they were in imminent danger when it happened. I guess the survived system of redundancy pair allowed them to safely stop the vehicle.

The one i more concerned is the reliability, currently i have much less confidence to drive it even slightly remote places.

 

[Cyber Man]

i am not too much worry about the safety concern becaus no one reported they were in imminent danger when it happened. I guess the survived system of redundancy pair allowed them to safely stop the vehicle.

The one i more concerned is the reliability, currently i have much less confidence to drive it even slightly remote places.

I agree! I guess we don’t have an option but to buy Basecamp tent . Your situation is more sticky, thanks to PNW rain! ?‍

 

[Spacenoddle]

I agree! I guess we don’t have an option but to buy Basecamp tent . Your situation is more sticky, thanks to PNW rain! ?‍

I can be blend in seamlessly into the Seattle landscape with that basecamp.…

 

[JBee]

i am not too much worry about the safety concern becaus no one reported they were in imminent danger when it happened. I guess the survived system of redundancy pair allowed them to safely stop the vehicle.

The one i more concerned is the reliability, currently i have much less confidence to drive it even slightly remote places.

That is not a good risk assessment.

Being not being able to start your car in the garage is not the same risk as it happening whilst towing a loaded trailer down a steep curvey mountain.

Also its super important to note here that SbW has "redundant" system to keep the vehicle "fully functional", and not so one can fail and the other offers reduced performance.

In this case the reduced performance of the steering was a failure of those redundancies that should have kept it "operationally functional."

What the error was on the sceen, does in no way indicate the seriousness of the risk, but an assessment of what functionality failed, and at the same time, does.

Further the brakes have no such redundancy, nor are SbW and are like any other EV vehicle with a electric booster. So if they fail as well as the SbW, and at the same time, the problem is a real safety risk i would never ignore, and am trying to highlight here.

The braking issue alone means you have a runaway vehicle if the person driving is unable to produce enough pedal force to slow it down by muscle alone, on top of that being confronted with a steering that does not behave as fast or as expected. Along with a series of critical error messages flashing at you dividing your attention.

At a minimum this will cause a high stress situation in most drivers and that alone is a risk in itself. Throw in screaming wife and kids from erratic driving etc and you have a recipe for disaster from the situation alone, even if there was still "some" functionality left.

These things are compounding problems that should never co-exist at the same time.

There is absolutely no reason whatsoever that the SbW error should be allowed to occur at the same time the brake booster does, because of a power problem. Then have your hand brake electrically actuated as well.

This is madness and being tested on civilians in the public domain.

Put the brake booster on its own independent circuit from the main pack, or even it's own little battery for all I care, or boost it from the CT air tank like old ICE did with engine vaccuum.

At least then you have a chance to stop with the foot or electric handbrake And only have to deal with one critical failure at a time, like the SbW.

This "no-part is the best part" nonsense has to stop at the point the sum of your parts lose any meaningful functionality.

If this was a isolated case then thats one thing, but there are whole series of vehicles with critical errors and power problems, and on top of that for apparently different part failures with the same functional error.

This is troublesome to say the least.

 

[CyberGus]

our blind love shouldn’t make us claim that steer by wire in CT right now is as safe as it’s on an airplane. It’s not apples to apples. Probably in the future it might be but not right now. Airplanes quality check is insane.

Please Google "737 MAX"

 

[CyberGus]

Do y'all have some secret source of insider information that the rest of us lack? Because I'm not aware of any confirmed first-hand reports of Cybertruck going dead-stick. The cases reported by forum members indicated reduced function, not total control loss.

Those physically and/or mentally unable to operate a motor vehicle during an emergency should strongly consider leaving the driving to the professionals, or accept the risk. Shit goes sideways sometimes.

 

[Cyber Man]

Please Google "737 MAX"

I'm not saying Airplanes are 100% safe. All I'm saying is that if a feature tech is taken from a higher sophisticated tech, then the safety of one shouldn't be compared to the other in the name of "same stats". It's like saying anything that drives on 3 wheels is as safe as Boeing. Rockets and space shuttles have even higher safety checks, but some astronauts have lost life with tragic accidents. When someone says steer by wires are used in airplanes, it doesn't make CT automatically as safe as airplanes, at least for now.

Do y'all have some secret source of insider information that the rest of us lack? Because I'm not aware of any confirmed first-hand reports of Cybertruck going dead-stick. The cases reported by forum members indicated reduced function, not total control loss.

I'm not debating about CT getting into a dead stick and causing fatalities. I can't speak for other members' stance. All I'm saying is if critical errors are reported because of steer by wire, causing the driver to do an emergency stop and tow the vehicle, it's less of safety concern and more of reliability concern, as @Spacenoddle said above.

Are you ok to experience this in the middle of nowhere? I'm mentally and physically fit and do track days with bikes faster than Beast, but I'm not OK to manage the hassles of an inoperable vehicle on my way back from night snowboard trip or while boon docking. I anyway need to worry about flat tire, range, etc. I don't want to add one more variable to the equation.

Steer by wire is one of the best features I like about CT. Tesla had the balls to do something that nobody could. If any concerns are reported, I don't like fanboys brushing it off saying the feature is as safe as an airplane's. Being a CT fanboy myself, it makes me cringe!

 

[NoMoGas]

@JBee already explained everything in detail. So I don’t have anything much to add on the technicalities.

Look, I love CT to my heart, but our blind love shouldn’t make us claim that steer by wire in CT right now is as safe as it’s on an airplane. It’s not apples to apples. Probably in the future it might be but not right now. Airplanes quality check is insane. Imagine getting on a plane and seeing a panel gap or pilot screen completely going blank or wiper unable to fully wipe off rain water. Those things have happened to early CT adopters.

When owners reported rust, I disregarded that as crap; science didn’t check out for that one. This issue, I’m not so sure. I’m confident when people write software, there will be bugs. I have shipped many bugs too . Call me a bad engineer but no software is perfect. If you aim for 100% perfection, you will never ship.

Tesla needs to investigate what caused this critical failure. We don’t know if it was one motor or two motors. We are just speculating. Imagine driving in a remote windy mountain roads at night and CT steer by wire failing. Let’s not compare this with the odds of tire blowout or getting stuck my lightning. Stats cannot be compared like that. We don’t have stats for steer by wire on CT, except this particular incident. So neither math nor science checks out here. The concern here is valid, but I’m confident Tesla will investigate and root cause it.

I would suggest you don't go near an airplane lol you would be amazed at how often things fail.

I cannot follow you down the rabbit hole that the steer by wire is somehow not safe. It is redundant. With redundancies built on top of that with the sensors. Based on the description of the failure we were able to determine that it was in fact one motor, not both. If it was both, we would've lost the ability to control the vehicle. Instead, he received a message on the screen that he then reacted to. Those messages are designed to get your attention for good reason and scare you into stopping the car. Also this so-called catastrophic failure resulted in no injuries, and no real incidents other than a freak out that got lots of clicks on the Internet. Truth is a simple reset probably would've fixed it, but I don't blame him one bit for playing it safe and having the vehicle towed. Just understand that that's why there are redundancies, because Tesla is playing it safe.

I am far more skeptical of Internet hyperbole than I am of the engineers at Tesla.

 

[cgladue]

I would suggest you don't go near an airplane lol you would be amazed at how often things fail.

I cannot follow you down the rabbit hole that the steer by wire is somehow not safe. It is redundant. With redundancies built on top of that with the sensors. Based on the description of the failure we were able to determine that it was in fact one motor, not both. If it was both, we would've lost the ability to control the vehicle. Instead, he received a message on the screen that he then reacted to. Those messages are designed to get your attention for good reason and scare you into stopping the car. Also this so-called catastrophic failure resulted in no injuries, and no real incidents other than a freak out that got lots of clicks on the Internet. Truth is a simple reset probably would've fixed it, but I don't blame him one bit for playing it safe and having the vehicle towed. Just understand that that's why there are redundancies, because Tesla is playing it safe.

I am far more skeptical of Internet hyperbole than I am of the engineers at Tesla.

Exactly, coming from a SpaceX avionics engineer I 100% trust her opinion then any of you guys like i said not dangerous, or life-threatening, just an inconvenience. It will get fixed, just chill. also like i said this is why i am not road tripping in the CT for a little bit after i get it, ill stick to my Model S

 

[CTInProcess]

The OP title must be changed - no where in the hit-piece, or the original tweet, or the OP provides ANY evidence for steer by wire failure! It could be as easily be 48v harness disconnect, or any other low or high voltage failure.

I agree! It was most likely user error. Tesla is great at what they do and would never allow this to leave the assembly line.

 

[JBee]

I would suggest you don't go near an airplane lol you would be amazed at how often things fail.

I cannot follow you down the rabbit hole that the steer by wire is somehow not safe. It is redundant. With redundancies built on top of that with the sensors. Based on the description of the failure we were able to determine that it was in fact one motor, not both. If it was both, we would've lost the ability to control the vehicle. Instead, he received a message on the screen that he then reacted to. Those messages are designed to get your attention for good reason and scare you into stopping the car. Also this so-called catastrophic failure resulted in no injuries, and no real incidents other than a freak out that got lots of clicks on the Internet. Truth is a simple reset probably would've fixed it, but I don't blame him one bit for playing it safe and having the vehicle towed. Just understand that that's why there are redundancies, because Tesla is playing it safe.

I am far more skeptical of Internet hyperbole than I am of the engineers at Tesla.

Some details would help your incomplete perspective. But if you are not willing to dive down the technical rabbit hole then there you won't be able to understand the nature of the concerns.

If in fact the systems were redudant and also isolated then your assumptions might be correct. Fact is there was only limited steering response with a SbW error and no brake assist with a brake error, with the same "Critical Failure" error. Those two should no occur at the same time if they had their own isolated redundant systems. Only one should happen at a time. If two happen they are neither redundant or isloated from eachother.

As for the comparison to aircraft this is complete nonsense.

1) most obviously Cybertrucks can't fly (!) and by far aren't so complex, neither have the same procedures and mandated maintenance and FAA certification for passenger licencing, and 2) the SbW is just a glorified electric steering rack used in all Teslas and EVs just running on 48V with a extra redudant motor. It is far and away not as complex or certified as a aircraft flight control system whatsoever.

Also Tesla engineers are not the only ones who have say how things should be done. Even EM admitted they dug their own grave with the CT. So there must of been issues getting the design to work.

 

[Dazureus]

The article was light on details and I haven't been able to follow if anything else has come out on this, but it does seem like there are a few posts about critical failures or system start issues that are concerning.

My take is that if the brakes (electric brake booster) and SbW system were heavy then the fault is in the 48 V system somewhere. In normal CANbus architecture systems, multiple ECUs will monitor the voltage system signal and trigger DTC errors for low or high voltage events but limited assist is only present when a fault is within the respective system itself. In the EPS that I work on, there can be three different kinds of faults due to internal diagnostics. Reduced performance, where overall operation is present, but some functionality is reduced or removed. Controlled shutdown, where there's a fast ramp down of EPS assist to zero, which can occur with torque sensor faults, and Immediate shutdown, where assist is taken away immediately. Steering fault feel is not an industry standard and is created as requested by the OEM, so I'm not sure what fault states Tesla is using, especially in the Cybertruck but it provide some information on what a steering internal fault would feel like.

Since the Cybertruck has a more centralized zonal system, the theory probably still applies. If the screen was still working, but throwing user visible errors to cease driving, I'm guessing the SbW went into limited assist mode due to some voltage fault and something similar happened to the electronic boost brake system. EPS steering systems can go into limited assist for any number of various reasons and that's just normal fault detection mitigation. The SbW hardware redundancies are present in case of SbW hardware component failures. Tesla said that each EPS powerpack is able to output enough torque to fully steer the vehicle, and under normal operation, each operates at half power. As JBee said, if both the brakes and steering to go into limited assist, then an anomaly is detected in the system outside of the steering or braking systems, and effectively "bypassing" the hardware redundancies.

For such safety critical systems, it would be nice if they were power isolated so this scenario wouldn't happen, but it can happen on a traditional 12V system. The only difference here is the SbW lack of physical redundancy. It would be nice to have a super cap or limited redundant battery on both systems that could provide full assist for a very short time when voltage faults are detected. I don't know that they don't exist, but this event suggests that something like that isn't present or the feature isn't implemented in this specific fault state.

The 48V system issue could be as benign as a BMS software issue affecting the charging cycle or something more serious like a bad wiring harness or traces in the board manufacturing. It's good that no one was hurt and the faults were detected and acted upon safely by the user, but it does warrant investigation and information dissemination to help bolster user confidence.

 

[BannedByTMC]

Those physically and/or mentally unable to operate a motor vehicle during an emergency should strongly consider leaving the driving to the professionals, or accept the risk. Shit goes sideways sometimes.

Indeed it does but your criteria would leave probably 90% of drivers unable to own a vehicle. Vehicles have been generally easy enough to control even in failure modes that the average person can do so safely in most situations.

Sponsored