Tesla Teardowns - Why is there a CLOCKSPRING?!?
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- Опубликовано: 26 окт 2021
- We take a look at one of the many thousands of often overlooked parts in a Tesla, or any modern car, the SCCM. (Steering Column Control Module)
This unit incorporates a high-resolution position encoder, all the control stalks, 2 microcontrollers, and a lot of mechanical goodness including the aforementioned CLOCKSPRING!
The main microcontroller is a Renesas V850 (UPD70F3579), the one for the steering wheel controls is an NXP S9KEAZ128AMLH.
Update: Here is the manufacturer: www.kostal-automobil-elektrik...
If you'd like to support my channel, I have a donation link here: / ingineerix 
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Thanks for another interesting video! Being a retired engineer I always enjoy teardowns with explanations.
Love your detailed vids on tear downs. You tend to get into all the really cool stuff so it's hard to make a specific request. Tesla's seem to have a mechanism that helps the car drive straight when the wheel alignment is off. I think it's part of the auto pilot system. Maybe do a tear down on that?
I would love to see that explained, Brandon!
@@dizzy2020 'owner's permission' is probably in the terms you have to accept to use the software; however, I can't call it consent because forced permission certainly isn't voluntary
There is no mechanism I am aware of to compensate for alignment problems. The only thing (shared by almost all cars) is the ackerman positive caster angle. This causes the wheel to self-center when driving forward. See "positive caster" here: suspensionsecrets.co.uk/caster/
@@Ingineerix Not long ago i had a wheel alignment performed on my model 3 and the alignment shop was frustrated with how after they aligned the wheels, the car pulled to the right. They couldn't get it straight. However after about a week it started to drive straight (mostly). Tesla charges a large fee (~$500) for a "calibration" when doing a wheel alignment so we concluded the car is somehow correcting itself. Amateur conclusion perhaps?
@@brandonbeck4794 I'd say don't go back to that shop. If they can't tell you why it's pulling or set it properly, then they don't know what they are doing, or their equipment is not working correctly. The only calibration is steering angle, and any decent shop will first set the wheel to 0 degrees and place a fixture on the seat to hold the wheel at 0 while they adjust the car. It will not need to go to Tesla if this is done. If they did it wrong, and there is an offset from 0, then the angle sensor has to be reset. This will also result in your wheel not being centered properly.
8 minutes and 55 seconds ago, I didn't know that I wanted to see a video on the SCCM because of course I had zero clue of what an SCCM was. Now of course I'd look forward to seeing more such videos. So what other parts do I want to see videos on? I certainly don't know but I'll happily enjoy whatever you choose to present.
Brilliant! Thanks for bringing us on your journey.
I've been enjoying these kinds of videos from other channels before finding yours. Sandy is good but yours is much more detailed and insightful.
Thank you bro!
I enjoy watching content like this baked out of my mind on some dank indica.
The SCCM module itself is actually made by Kostal. One interesting difference if you take apart the drive selector is that it is Hall effect, unlike the contact based approach on the turn signal. Presumably this was done to ensure the more important control is more reliable. I have a few of these modules and had to repair the little legs on the turn signal side on one.
Also LIN isn’t actually terminated at the sccm, but goes all the way down to VCLeft. Iirc, the LIN line passes directly through the connectors and travels to vcleft. The sccm doesn’t speak LIN at all.
Thanks Ryan!
@@Ingineerix I just don't like all that complexity, at all. I wish a company would build a SUV/ crossover and mid sized truck that can go 300 miles, just has a battery, motor in the front and motor in the back (for 4x4) and NOTHING else. No screen. No AI driving. No reverse camera. No electronically adjustable vents. Why are they a thing? I want hand crank windows and manual seats, manual mirrors, standard cruise control, speedometer, charge and temp gauges on the dash and nothing else; and make it for $14k. If a company built this basic, baseline utilitarian vehicle, it would be the next Henry Ford revolution and they would sell millions and millions of them. All people need is something that works and gets them there; we don't need a self driving spaceship with it's own personality that has an IMax theater inside it.
@@calholli no one would buy that. people are used to power everything(as unnecessary as it may seem). no one even necessarily "requires" 4x4... America is paved. Your build sounds like an ATV...
@@calholli So you don't want the statistically less likely to get into an accident Tesla with it's ADAS? You do want hand crank window regulators made out of crappy pot metal like the ones that used to break all the time in old GM vans? You do want an analogue instrument cluster that costs more than digital one? You don't want torque vectoring to make that dual motor setup worth the cost? You would rather change lanes with your fingers crossed hoping no one is in your blind spot because it's too much trouble to readjust the mirrors every time they get bumped or were set for a driver other than you?
I get it, I do, all those motors and gear trains for mirrors and seats and all are potential points of failure but if they're made or spec'd by a company like Tesla I trust that they'll do all they can to make them lifetime reliable and so I believe that the extra cost of such systems is well worth it.
@@calholli Not going to happen, for starters a lot of this "complexity" is legislated in the form of DOT regulations. For instance a reverse camera is now mandatory. That means you're getting a screen too. If more people really wanted a "bare bones" vehicle, then little small econoboxes would sell better. As it is most automakers are discontinuing these models as more people are buying large loaded uxury SUVs.
Thank you for the rundown. This is very interesting!
This is a great and underrated channel! Thank you for posting these teardowns and explaining them. Great for engineering nerds!
Coolest thing I've seen all week. Please keep posting!
Awesome video thanks for taking the time to film this
Also connected to this: three push buttons behind the driver airbag to sound the horn. May have been too simple to be mentioned. 😀On newer Model 3, also a steering wheel heater is available. Then some of these rolling ribbon cables actually get some minor load on them. I don't know the wattage though.
A nice detailed breakdown of the part and sub-assemblies. Thanks for the education Phil!
Thanks for the video, very interesting systems in this steering wheel
Great job , nice explenation ! Thank you from Italy
Another great video, thanks!
Amazing detail, thanks! Subbed!
Nice breakdown and explanation! Thanks!
Ahh. My '67 Chrysler Corp " Dr. of Motors" cert is now updated. Thanks!
Very cool. It's a lot more complicated than when I took the steering wheel off my 1987 Honda Civic because I was having trouble with the clock spring contacts.
The old cars had a wire that went through the steering shaft for the horn, the only thing on the wheel. The wire just twisted over the length of the shaft. Then they started using a slip ring arrangement on newer cars still for the horn. When computers and air bags started to be used they went to the clock spring because they needed more connections. GM and some other manufacturers started using a series of resistors for the switches that only required 2 wires, and the computer read the voltage to determine which switches had been pressed. Since then there has been several different approaches to solve the problem. Some might even bring the CAN bus to the wheel. Just remember, don't spin the wheel if the steering shaft is disconnected !
Thanks! I always wondered how that was done. I previously assumed they just kept a crappy slip ring, and just sent a digital signal through it (whatever protocol with heavy error detection and repetition ) Nice to see this mechanically robust solution .. and dual sensor setup. I imagine the dual sensors can also detect and compensate for the gear slop
The dual sensors are needed to detect greater than 360 degree angle and do so in an absolute manner. There are 2 mechanisms built in to remove the "gear slop" (backlash), as this would definitely result in measurement error. The output of this is used for autopilot as well as stability control, so it has to be accurate.
awesome video - keep it up!
Excellent stuff as usual.
I love your content. I mentioned this in a previous comment, but wanted to encourage you to use a pointer when appropriate, it would be very helpful to both parties 😉
Great description. The rolling ribbon cables are not really in the form of a clock spring (a real clock spring doesn't fold over at one end and roll that way), but the early examples were, and the name persists.
Incredible seeing all those PCBs and CANBUS in there just for the clock spring. I'm working on disassembly of a 2015 Fiat 500 and they just use a resistor ladder for many of the steering wheel buttons, and the clock spring just connects to three different plug-in connectors that go straight down in a huge bundle of wires to the BCM
Thanks! Very interesting
This is why technology evolves over time and takes many generations of engineers. I would have never ever come up with this idea. Ingenious.
loved it
i didnt knew its that complex
pz keep up the good work
love more technical parts explained
Another incredible video. Thank you. This kind of gives a new meaning to chip shortage notion.
Very interesting. Great explanation.
Love these tear downs and your insight.
There are so many engineering marvels hiding around us in daily life. This is a great example and a great education.
I like the sound of your voice and you have a really clear narration style.
Thanks! Glad you enjoy it!
MORE videos with this level of detail, please!
Thank you, very interesting
great video!
The gears according to an automotive engineer, the twin gears that rotate differently or opposite directions also serve as error detection in case of a sensor failure.
The car knows exactly what to expect since it's a fixed ratio, anytime it's not what is expected. It knows something is faulty which depending on manufacturers have multiple fail safe modes such as disabling stability control or throttle input since the car can no longer rely on data provided by the steering angle to determine the direction the driver intends to go.
Great video
Peak Tesla electrical content thank you!!
Show us EVERYTHING! I love seeing what Tesla does with their cars.
You like seeing stupid stuff, b/c lazy engineering low quality control 🤣
You could tear down anything in a Tesla and I’ll watch it.
Would be interesting showing more detail of the LV architecture used by Tesla. I'm sure it will be drastically different from other automakers
Mighty interesting, I never thought about that.
Very interesting & explained a lot why the clock springing my GMC Chevy Sierra 1500 air bag light came on intermittently. Some days the warning light would flick off& on 7 times then go off completely only ten minutes later the warning light would come on again & stay on. I tried removing the fuse to the dash light but that was worse in fact the warning light stayed on continuously! So as it’s almost impossible to purchase another clock spring …. I finally removed the dash warning bulb putting the concern out of my mind! Certain models have sensors under the body work at the front of the vehicle but I could never find them & they to are as scarce as hens teeth!
So after watching your video I’m inclined to think that there maybe too much side play in the steering column beneath the air bag itself either that the electronic stuff is buggered!
Love it!
That was remarkably complicated! Thank you so much for breaking it down for us.
I would love to see the Yoke steering wheel's components broken down for us because it has no stalks. Maybe it is simpler without stalks or maybe it is more complicated?
Thank you so much!
Much less rotation course likely makes it mechanically simpler, without those wrapping flat cables.
I just had this clock spring ribbon come flying out due to me forgetting to disconnect the plug before removing the steering wheel. Insane length and I’m unsure if I’m going to be able to spool it back in correctly. What an absolute headache I’ve made for myself.
It would be INCREDIBLY timely right now to review/overview the charge controller module that contains SWC and now PLC. Lots of people talking about Tesla's move to open Superchargers to third parties - applicable right now in Europe where Tesla already has switchable PLC/SWC circuits (what was previously just J1772 was extended with PLC capability in ... what, late 2019 and up Model 3/Y when the Y came out?), and my theory is that Tesla may be moving to unify CCS as the overall standard. Could be perfect timing if you have one on hand to talk about PLC (J1772/ISO15118) and SWC (Tesla SC/UMC) signalling and how it relates to interoperability.
Done! ruclips.net/video/0lxxOsLcNQQ/видео.html
So interesting thanks. Still much to learn. FSD make these before simple parts so complicated.
Another awesome video! Thank you! Can you make a video on how Re-Gen Breaking works in the Tesla?
Great tear down!
Do you think a heated wheel retrofit for early Model 3s will be possible? I’ve done the retrofit on a Touareg… I’d love to have it on the Tesla.
The steering angle sensor on that 04 VW was just optical, kind of like a ball computer mouse. The clock spring had fingers that interrupted optical sensors. The Tesla gear arrangement seems way more accurate!
My old 91 Mercedes actually uses a slip ring for the airbag! If the car sits for a long time the ring seems to get some corrosion and the SRS light will come on until the wheel is turned some.
No, there is no control system for it, so even if you added it, there is no easy way to enable it.
@@Ingineerix Mechanical switch on the steering column?
@@user2C47 It would have to be on the steering wheel itself. There is no extra pin on the clockspring, so your switch would have to live on the moving part.
Love these videos, there what make RUclips great.
The Sandy Munroe of vehicle electronics.
Yes! More parts!!
I had an issue with the SRS system on my Model Y, and felt the components were not developed under Tesla's "roof" I would appreciate you insight into the individual systems that you conclude that were Tesla designed or contracted designs.
Appreciative of your content.👍
BTW I was impressed that the problem with the SRS was diagnosed OTA. The parts were ordered, and it took them 2.5 hours to replace the faulty parts. Normally a two trip process, and at least a 3-4 hr job.
Correct, the RCM (Restraint Control Module) and airbags are outsourced.
I have a question you might know. How does the car sense the amount of force I turn the steering wheel so it knows how much the steering assist motor has to do? My steering assist is acting up a little. Trying to figure out where to troubleshoot
I was under the impression that flexible pcbs, flex cables etc. are not designed to be moved too much. but here they flex every time the turn signals are used.
Ones made with Kapton Polyimide are very robust, they can flex almost forever as long as the bend radius is respected.
amazing
Amazing engineering. Stuff we take for granted on a daily lol…to engineer something like this, the designers probably had to engineer the driver circuit for just that connection to compensate for inductance to protect the data integrity between the steering wheel computer and the steering stalk computer
Yes! So many details people take for granted. There was a whole TEAM responsible for just this SCCM (steering column control module).
So how does the power steering adjust to different steering settings?
I haven't pulled a tesla apart, but as you say. the clockspring is generally for sensing to the airbag and horn, as well as possible steering wheel buttons. Its interesting what they have, but I guess the hall effect system is used for the FSD system, as well as steering angle sensor as well. So looks complicated, but is probable the easiest way to perform the tasks.
I want a model "Plattfuss: the yoke of the model Plaid. So much less to go wrong. I guess it will stay wired a bit longer but technology will not halt. Some form of rad-com will take over one day.
In aviation we have the FAA to presumably check if a plane is safe to fly although it fail miserably on the 737 Max. On cars what administration is checking them. In the old days the steering wheel could get harder when the power steering failed but we still you could riches the safety shoulder. In your demonstration I don't see any redundant device allowing me to go to a safe place if the steering fail. Hopefully the National Transportation Safety Board (NTSB) will investigate the crashes and gives some advises on how to improve the situation, like having assisted steering where the driver still can control the car when the electronic fail.
Very interesting. And to think that the next gen Tesla’s won’t need any of this with full auto / steering wheel delete.
Me at 3AM: Sees title of the video. Well lets find Out
Looks like the eccentricity allowing ring thus allows the main gear to be pushed off-center to cancel gear play
I'm interested to know if the central clock spring part at point 3:25 min in the video is available from Tesla spares and how much they sell it for? When I had to replace a basic clock spring in a legacy car brand, I was socked by over inflated dealer price for the part. Basic because it had one ribbon, (four wires for horn and airbag) and plastic casing with connectors. Not nearly as complex as this Tesla one. Thanks for sharing your expertise and the great video content.
No, not only would the parts not be interchangeable (I can almost guarantee), but parts like these are only sold as a complete assembly. If you are on a budget, try a pick-and-pull junkyard.
Great video, thanks! After the car has been sleeping and I open the drivers door, there's a click which comes from the frunk area, then a click from the rear of the car. Can you do a video of what's going on and the parts involved? Thanks again.
Sure, That's a good idea. I'll add it to the list! The clicks in the rear (under the back seat) is a "Click-CLUNK" noise which are the main battery contactors closing to enable the high-voltage system. The only thing in the front that's noisy is likely the A/C compressor (Heat pump on never cars). Once the car wakes up, that also fires up.
Great vids man! Can you do a deep dive on how Tesla model Y or 3 implements regenerative braking? IMHO, it's one of the best features of driving an EV.
Regen is pretty much automatic on a car using an inverter with AC motors. Here's a good summary: chargedevs.com/features/regenerative-braking-a-closer-look-at-the-methods-and-limits-of-regen/
I knew about clocksprings in steering wheels, but I didn't know about how precise the magnets and gears were. They must utilize this for making sure the driver has their hand on the wheel for Auto Pilot as I've noticed it just takes a bit of resistance in order to prevent the nag. Did you find any motors in this assembly at all? My first guess to how that worked was if there was resistance on a small motor or something. But now, having seen this, it looks like it just checks if the magnets have moved enough over a period of time. Or perhaps they have it programmed to detect natural vibrations from the road, so there would be more noise, so to speak, if the wheel wasn't being held steady? I'm not sure, but knowing that this is done through software makes it even cooler to me!
This is really fascinating and does give me a great appreciation for engineers! Thank you for sharing!
The motor (for power steering and/or automatic steering) is usually on the steering shaft or steering rack, not the steering wheel.
Huh i always knew there was a clock spring cable going up to the steering wheel but I was a little puzzled by it. I mean you can slip ring CAN signals, though that's usually just LIN to wheel and that's even easier; and if that hadn't been an option, all sort of inductive connections are conceivable. I had somehow completely forgotten about the pyrotechnics! Obviously when we worked on the stuff on the software for the headunits etc we didn't often need the steering wheel, using CAN simulator instead, but those that we did have, didn't have the airbag.
A slip ring is going to be less reliable, and arguably more costly than this simple flex cable clockspring. They definitely can't chance airbag connections on a slip ring.
Would be interesting to see a comparison to the plaid yoke. No stalks but also the horn became a button. Seems like the scroll wheel Lin module could be doing more or I would bet they are down to 1 circuit board
I already had a look, Looks like a similar module, just no stalks, and more going on in the yoke itself, as there are 2 sets of capacitive triangulators to sense the buttons (one on each side) as well as haptic feedback.
ugh... it annoyed mee in my prius, Now my 2015 Tesla changes the station when I turn the wheel. Thanks for the video!
@Ingineerix are the stalks swappable? Could the ribbon connectors be swapped between sides? We’ve three cars with the indicators on the right and the model 3 on the left. I keep turning on cruise control as I turn right arggh. In a software defined car they should be a setting to swap sides but I’m having to look at more drastic measures. Thanks.
There is no way to do it via software alone as there are hardware differences between the sides. (stalk button is 2-stage on left, high beam toggle on left, etc) Now with some work it may be possible to build a swapped set, but it's non-trivial and would require cracking all that open.
I think my sccm went out due to steering controls and horn not working on my model s. Do you know what part fails to causes this?
This is super interesting. Can you comment on how other modern manufacturers design the same part? Is it more or less complex? This seems likes an area where you can simplify and save.
Wow!
Now I understand why Elon wants to reduce the number of stocks on the steering wheel.
Removing the stalks won’t eliminate most of this. I have the plaid and it’s probably more complex with all the silly haptic buttons.
Do you by chance have anything that indicates where the magnets should be positioned? I had to remove my assembly because it was squeaking and after 4 service attempts, Tesla couldn’t fix it the lubed many points with some silicone grease but the magnets apparently are out of alignment.
I'd recommend just getting a salvage assembly, it's cheap enough that it's not worth your time: www.ebay.com/itm/403950782718
Is there some redundancy in those 4 ribbons, or are there problems if just one is broken?
Can see several parts which could be reduced. Hopefully we will see cost reductions on the next version.
Would like to know how to make the M3 trailer hitch pigtail work. Looks like LIN with a plus & minus
Can you do a video on how to talk the stalks off of the SCCM?
I sort of did this already: ruclips.net/video/62txKc7EtCA/видео.html
Wonder if Plaid is different.
Seems to me it could be done inductive. Alternatively do a non linear 90 degree steering wheel action, then a slightly loose cable will suffice.
That stalk should go as well. Should be a touch display in the steering wheel face. And yes, there is still room for airbag, spare me.
I believe all cars use this spring since 1990. My 1993 Passat had one for airbag and I was repairing it.
Don't really understand what's all the surprise here about.
I would love to see how the brakes work. and power steering.
That's genius using ribbons.
Tyre pressure sensors are interesting too. Not sure what broadcast protocol they use.
So, based on the title I assumed you were going to talk about why Tesla isn't using a slip ring or wireless for the auxiliary steering wheel functions, but you didn't really address this - the obvious answer is that they have a clockspring because almost every vehicle made in the last 30+ years has a clockspring. Tesla is known for doing things different but what are their options? They could use a slip ring, but maybe they're too expensive? Wireless is being introduced for battery pack management so that seems within the realm of possibility.
Very VERY few people know what a "clockspring" is in this context, so I thought it would make a good topic. Sorry to let you down, but Tesla does this just like all the others.
I accidentally got the clockspring ribon lose but nothing is broken. By watching your video i think i would be able to get the ribon spirals and move as seen in your video. If i do, will the Tesla Model 3 recognise the clockspring automatically or i need to do something in service menu? Or once it comes off even if i get it back, Tesla will not recognise it anymore? Currently my Tesla Model 3 2020 AWD is complaining that buttons are not available. I would be grateful for your thought.
If the buttons on your wheel are not working, then the clockspring is broken somewhere even if it doesn't appear that way. Best is to replace it.
@@Ingineerix Make sense, thank you
@Ingineerix after putting all the ribbons as you showed here and also put it in center position "2.5 turn both ways", with my surprise buttons & horns are working fine. I have no idea how i managed to put the ribbons though. It just happened upon trying for an hour. Thank you so much for showing how it should be and works, as only because of your video i was able to put it back together. Please continue such videos as no one does it like you.
Obviously these are fun breakdowns, and thank you for them, but it would be more interesting to analyze parts that are truly unique to Tesla.
As we know, like most other automobile makers, Tesla sources most of their parts from external vendors: steering, suspension, brakes, wheels, tires, glass, chemicals, dashboards, touchscreens, cameras, etc. Contrary to popular opinion, Tesla is not totally vertically integrated.
However Tesla does make the most important parts of an EV: motors, battery packs, some electronic hardware, most software. Software is really the key to their outstanding functionality, and Tesla is far better at it than most other car makers. Really the engineering of every aspect of the cars is excellent.
This stands in contrast to many other EV makers who get their battery packs and motors from external suppliers like LG, etc. (That would be a bit like GM or Ford buying internal combustion engines from Hyundai.)
Over my engineering career, my theory with electronics has been, If they did not want you to take it apart they would not have put screws in it.
I was working for Kostal and indeed the whole module is not designed by Tesla. For sure there are very interesting design solution, but also some of them are not so reliable.
Hi would you happen to know if the electric connector for the canbus to the vehicle is a standard kostal connector or a special for Tesla ?
When the Tesla model S came out it used stalks from Daimler Benz. This may have been changed in the facelift.
They used the same supplier as Diamler. Diamler, and to my knowledge, zero other automakers make their own SCCM. In Tesla's case they use a supplier called Kostal: www.kostal-automobil-elektrik.com/en-gb/empathy/drive-controls/
Is this the first steering that you see from the inside? That‘s not particulary uncommln.
I'd really like to know if it's possible to retrofit a heated steering wheel in a 2018 Model 3.
Yes, but without Tesla's cooperation, or someone hacking into your ICE (Car Computer), you can't enable it.
Tape a load of 'hot hands' to the rim, or get yourself some gloves or bigger nads.
Man….this whole assembly is begging to be redesigned and simplified. I can almost hear Sandy Munro weeping.
Thanks! Very interesting to learn these ingenious solutions…R you still supporting requests to jail break a salvage title Tesla? I’m thinking about purchasing a model S w minor accident and would like to get off Tesla updates and enable Supercharging, please let me know?
Yes, depending on year.
Great ! it’s a 12/‘16 MFG date Model S ? So probably a 2017 model year please LMK and how to contact w you if this works, I’m in the Bay Area Thanks so much !
@@stevenroe2154 Email me, my email is listed in my channel's "about" page.
Ok sorry, I’m not seeing your email on about page
@@stevenroe2154 On your computer (not phone) go to ruclips.net/user/ingineerixabout scroll down to "details" and click "View Email" (You have to be logged into RUclips).
I actually had this very part fail on my Model 3 earlier this year. It eventually got serious enough that the car wouldn't go into Drive. Tesla service replaced the entire module as you'd expect.
I love the idea of using two different sizes of gears for the Hall effect sensors to detect absolute steering wheel position with high precision. Are the tooth counts on those gears prime numbers?
I have only seen one of these fail, and it was due to someone spilling a coffee on the steering wheel, which somehow got into the electronics. But almost anything can fail. Usually without external causes (coffee), there is a "bathtub curve" where complex parts either fail really early (infant mortality), or they last a long time and fail well past their design life.
@@Ingineerix indeed. Mine failed after 3 years without any coffee spills or anything like that. Rare but it happens I guess.
@@pepstein Did Tesla cover it under warranty? Where do you live? The one major enemy of these things might be dust and/or humidity.
Yeah they replaced it under warranty. Car spent most of its time garaged. Bay Area CA. No dirt roads or other sources of dust.
What could go wrong? ...and I'm not talking springs here. If those are not mil. spec. electronics I'd be worried. I suppose that I'm worried.