High speed braking instability - ABS/ESP bug?

[electrifier]

Based in Germany I am new to the "Tesla World". I took delivery of the M3 last week.

I guess with first M3s coming to Germany only last month, there is limited high speed handling experience with the car on "normal roads". Nevertheless, I would like to find out if anyone has had the same problem as me.

Yesterday I was driving at max speed 233kmh for an extended stretch (German Autobahn), the handling through long radius bends and slight undulations was very firm and reassuring. The M3s high speed handling very positively surprised me and is absolutely up there with a high end Audi/BMWs etc (which are made for high speed and the M3 I guess isnt). So far so good.

Later I was travelling at about 200kmh through another long radius bend (without undulations) and had to slow down due to traffic. As I touched the brakes at roughly 50% max brake power, the car suddendly got completely unsettled, ABS/ESP on all 4 wheels set off one after the other trying to stabilize the car only making it worse. The car all of a sudden felt like riding on soap! This ABS/ESP situation lasted for - what felt a few seconds - it was probably 2s? This is not a speed at whicih you want to crash out! Shocked of the experience I then reduced speed and a similar situation happened a few minutes later at around 160kmh (Darwin Award worthy?). For the record, I am stating below the conditions at the time.

After this incidence my confidence in the handling plummeted, as I don't know what awaits me next! Most disconcerning is that the car otherwise handles and brakes (in a straight line, even from high speed at 100% brake power) fine, so it would appear to be an electronic malfunction only under certain conditions.

I can only warn you not to "try this at home" as it was very seriously dangerous, but I would be appreciative of any advice or experience any of you may have had.

Car: Model 3 AWD LR 19"
Payload: only 70kg driver
Software: 2019.8.3 da116a6
Temperature: 14 degC
Road surface: Concrete
Dampness: Dry (warm afternoon)
Tyres: "summer tyres"
Tyre pressure: 2.9bar
Light: daylight
Road: Germany, A20 between Lübeck and Bad Segeberg, left hand curve near Mönkhagen travelling on left lane.

 

[dfwatt]

Based in Germany I am new to the "Tesla World". I took delivery of the M3 last week.

I guess with first M3s coming to Germany only last month, there is limited high speed handling experience with the car on "normal roads". Nevertheless, I would like to find out if anyone has had the same problem as me.

Yesterday I was driving at max speed 233kmh for an extended stretch (German Autobahn), the handling through long radius bends and slight undulations was very firm and reassuring. The M3s high speed handling very positively surprised me and is absolutely up there with a high end Audi/BMWs etc (which are made for high speed and the M3 I guess isnt). So far so good.

Later I was travelling at about 200kmh through another long radius bend (without undulations) and had to slow down due to traffic. As I touched the brakes at roughly 50% max brake power, the car suddendly got completely unsettled, ABS/ESP on all 4 wheels set off one after the other trying to stabilize the car only making it worse. The car all of a sudden felt like riding on soap! This ABS/ESP situation lasted for - what felt a few seconds - it was probably 2s? This is not a speed at whicih you want to crash out! Shocked of the experience I then reduced speed and a similar situation happened a few minutes later at around 160kmh (Darwin Award worthy?). For the record, I am stating below the conditions at the time.

After this incidence my confidence in the handling plummeted, as I don't know what awaits me next! Most disconcerning is that the car otherwise handles and brakes (in a straight line, even from high speed at 100% brake power) fine, so it would appear to be an electronic malfunction only under certain conditions.

I can only warn you not to "try this at home" as it was very seriously dangerous, but I would be appreciative of any advice or experience any of you may have had.

Car: Model 3 AWD LR 19"
Payload: only 70kg driver
Software: 2019.8.3 da116a6
Temperature: 14 degC
Road surface: Concrete
Dampness: Dry (warm afternoon)
Tyres: "summer tyres"
Tyre pressure: 2.9bar
Light: daylight
Road: Germany, A20 between Lübeck and Bad Segeberg, left hand curve near Mönkhagen travelling on left lane.

Were you in autopilot or in traffic aware cruise control? There are reports of cars in autopilot doing sudden breaking., although I believe that has been regen braking only and not friction brakes. The other question is whether the conditions were wet. At speed especially if you have not touched the brakes for miles, sudden brake actuation can make the brakes grabby and unpredictable if they are getting a real soaking. This can make for some unstable actuations particularly if you're trying to stop quickly and it sounds like you were slowing down heavily at the time.

PS scratch that idea looks like it was warm and dry. So long story short I'm not sure. If it wasn't some sort of Phantom actuation of automatic emergency braking - did you have that turned on? - I'm not sure what it would be. We've never had any breaking and stability in our cars but we've never really done much more than regen and an occasional quick stop with friction brakes and not from high-speed either. So I'd be curious if anyone else has described anything like this. The guys who have tracked the car have never described it either

 

[electrifier]

Thanks. Automatic emergency braking is a possibility! I just checked, it was set to "on".

However, the deceleration did feel some margin away from "full lock" braking, it felt like they were engaging in turns (I could hear the typical ABS/ESP sound from a different tyre each split second) giving the car a swirling like motion (only few degrees of rotation of course, otherwise I would not be here to write this...). Also the emergency braking is set off by sudden braking and the overall setting of this incident was very controlled and the need to brake was not identified suddenly. The brake pressure was also only moderate.

Even if it was automatic emergency braking, it doesn't change the fact that the car completely lost its "line" and overall I felt a very long way from being "in control" of the situation.

further details:
Autopilot: off
Driving mode: standard

 

[dfwatt]

Thanks. Automatic emergency braking is a possibility! I just checked, it was set to "on".

However, the deceleration did feel some margin away from "full lock" braking, it felt like they were engaging in turns (I could hear the typical ABS/ESP sound from a different tyre each split second) giving the car a swirling like motion (only few degrees of rotation of course, otherwise I would not be here to write this...). Also the emergency braking is set off by sudden braking and the overall setting of this incident was very controlled and the need to brake was not identified suddenly. The brake pressure was also only moderate.

Even if it was automatic emergency braking, it doesn't change the fact that the car completely lost its "line" and overall I felt a very long way from being "in control" of the situation.

further details:
Autopilot: off
Driving mode: standard

For sure that has to be considered both puzzling and obviously very concerning. I would definitely have Tesla plug the car in and give it a thorough electronic check up.

 

[electrifier]

would Tesla have access to comprehensive "black box" data of the time of the incident?

 

[dfwatt]

would Tesla have access to comprehensive "black box" data of the time of the incident?

Good question. Did you have the teslacam activated? If so they could look at the files generated but I don't know about other levels of data harvesting. You have to ask Tesla.

 

[electrifier]

Did you have the teslacam activated? .

No, not used that feature so far.

 

[22522]

If you press the right scroll wheel and say, "bug report" then state what happened, this is supposed to tag the complaint with data. Not sure if that really happens.

 

[OPRCE]

Take this up with Tesla Service urgently as it is a severe hazard! It sounds like ESP freaked out when heavily braking from high speed.

Don't think AEB could be have been involved unless you heard an alarm tone?

Have had my S100D up to 255kmh on similar roads in Germany without a problem, handling was always smooth and predictable.

TBH I would drop your car with them until this problem is properly diagnosed and fixed, it beats running the risk of having to be scraped up off the Autobahn next week. Firmly demand a loaner and tell them to take as long as they need to get some very clear answers, otherwise your next stop will be government offices/newspapers!

If you press the right scroll wheel and say, "bug report" then state what happened, this is supposed to tag the complaint with data. Not sure if that really happens.

The bug report does not automatically get sent to Tesla, you still need to ring Service and have them retrieve it.

 

[electrifier]

It sounds like ESP freaked out when heavily braking from high speed.

I have the same suspicion

Don't think AEB could be have been involved unless you heard an alarm tone?

Pretty certain there was no alarm tone. Definitely no "warning lights" (which go off on other cars on emergency braking)

Have had my S100D up to 255kmh on similar roads in Germany without a problem, handling was always smooth and predictable.

That is how I know ALL half decent cars to handle in the same situation.

TBH I would drop your car with them until this problem is properly diagnosed and fixed, it beats running the risk of having to be scraped up off the Autobahn next week. Firmly demand a loaner and tell them to take as long as they need to get some very clear answers, otherwise your next stop will be government offices/newspapers!

I relative "lost" his Tesla to their service for a month before, but you are right, this is the right course of action!

 

[electrifier]

It sounds like ESP freaked out when heavily braking from high speed.

I have a hard time to believe such ESP malfunction is isolated to my car as the ESP works fine in other driving conditions. To me it smells like a systematic flaw. We will see what Tesla has to say...and I would be interested to hear if other people are having similar problems.

 

[OPRCE]

I have a hard time to believe such ESP malfunction is isolated to my car as the ESP works fine in other driving conditions. To me it smells like a systematic flaw. We will see what Tesla has to say...and I would be interested to hear if other people are having similar problems.

Tend to agree, the whole thing may have been programmed by the intern, who left the image of a large test-elk lurking around in there or something!

 

[SammichLover]

I've been only a bit below 160kph, roughly 150kph, during first segment of turn 2 here when I was late in braking.

<edit> Fixed image, direction of travel is clockwise on the red path. Blue and magenta are no-go, used for smaller loops.

It felt a bit off, not its normal rock solid self, but nothing that flat out scared me as you describe. I chalked it up to "braking while cornering is sub-optimal". For scale that front straight is about 400m long (1/4 mile). I assume that's a lot tighter turn than you're talking about, although I wasn't mid-turn doing this. No way I'd be able to hold anything close to 150kph through that turn, which is why I was using friction brakes rather than just regen. A Radical with a very experienced driver that was driving this course that day was, I understand, only in maybe the 130kph range for that turn.

Another difference from your case was that I had just been using the friction brakes, and let off, at the end of the straight scrubbing a bit of speed from a peak of about 180kph down to that 150kph. I let off the friction brakes as I turned in, then went back on to scrub a bit more speed.

P.S. As an aside I'd love to hear what kind of Wh/km you are seeing for holding a steady state speed at say 180kph. I'm trying to get an estimate for a distance road race that I cannot run a test race on. As we no longer have roadways that have legal speed limits like that, it is legally dubious for me to measure this myself.

 

[OPRCE]

Based in Germany I am new to the "Tesla World". I took delivery of the M3 last week.

I guess with first M3s coming to Germany only last month, there is limited high speed handling experience with the car on "normal roads". Nevertheless, I would like to find out if anyone has had the same problem as me.

Yesterday I was driving at max speed 233kmh for an extended stretch (German Autobahn), the handling through long radius bends and slight undulations was very firm and reassuring. The M3s high speed handling very positively surprised me and is absolutely up there with a high end Audi/BMWs etc (which are made for high speed and the M3 I guess isnt). So far so good.

Later I was travelling at about 200kmh through another long radius bend (without undulations) and had to slow down due to traffic. As I touched the brakes at roughly 50% max brake power, the car suddendly got completely unsettled, ABS/ESP on all 4 wheels set off one after the other trying to stabilize the car only making it worse. The car all of a sudden felt like riding on soap! This ABS/ESP situation lasted for - what felt a few seconds - it was probably 2s? This is not a speed at whicih you want to crash out! Shocked of the experience I then reduced speed and a similar situation happened a few minutes later at around 160kmh (Darwin Award worthy?). For the record, I am stating below the conditions at the time.

After this incidence my confidence in the handling plummeted, as I don't know what awaits me next! Most disconcerning is that the car otherwise handles and brakes (in a straight line, even from high speed at 100% brake power) fine, so it would appear to be an electronic malfunction only under certain conditions.

I can only warn you not to "try this at home" as it was very seriously dangerous, but I would be appreciative of any advice or experience any of you may have had.

Car: Model 3 AWD LR 19"
Payload: only 70kg driver
Software: 2019.8.3 da116a6
Temperature: 14 degC
Road surface: Concrete
Dampness: Dry (warm afternoon)
Tyres: "summer tyres"
Tyre pressure: 2.9bar
Light: daylight
Road: Germany, A20 between Lübeck and Bad Segeberg, left hand curve near Mönkhagen travelling on left lane.

One other recommendation, post this cautionary tale to TFF Forum - Tesla Fahrer & Freunde if you have not done so already, as that is probably where other such cases will be found, if they have happened.

 

[electrifier]

It felt a bit off, not its normal rock solid self, but nothing that flat out scared me as you describe.

The scenario sounds and possible malfunction sounds very similar, you were slower, so maybe with lesser effect.
Are you driving on the track with ESP switched on?

P.S. As an aside I'd love to hear what kind of Wh/km you are seeing for holding a steady state speed at say 180kph.

The figure I have is 400kwh/100km at 190kmh and about 450 at 200kmh. Its relatively accurate but not precise because I have so far not found a way to reset the "trip data" from the steering wheel (using the touch screen at those speeds is a bit mad). I also know that traveling at 233 steady state uses considerably more than 600kwh/100km because it was consistently off the standard graph (which ends at 600).

Just to reconfirm: my personal driving mode at the time (including the braking) was "fast cruising" and I was in no way pushing the car. Another detail: there was very little wind (about 8 knots, which I know because I checked to validate the economy figures)

 

[electrifier]

One other recommendation, post this cautionary tale to TFF Forum - Tesla Fahrer & Freunde if you have not done so already, as that is probably where other such cases will be found, if they have happened.

Good point, thanks, will do.

 

[VT_EE]

This sounds like a software bug to me. Tesla doesn’t get a lot of testing at those speeds so you guys are unfortunately beta testers for high speed driving. Report it to Tesla, but I doubt there is anything the service center will be able to fix. They will be able to report the issue to their engineers though.

 

[SammichLover]

Are you driving on the track with ESP switched on?

It is AWD like yours, no way to turn it off or alter it [yet] short of disconnecting one of the wheel sensor wires, which would get rid of ABS as well. I’m not so crazy.

I was using non-stock wheels, 200 treadwear quasi-track street tires. Slightly shorter & wider than stock tires & sidewalls same height as yours. They definitely have more grip than the 19” A/S Continentals which I assume are shipped stock in Europe, too?

What it felt like to me is I was putting the car near the edge of the rear end wanting to try pass the front, and there was a bit of work going on to not let that happen. Truthfully I was putting a lot of the car here, this isn’t normally what you want to do in this corner. Lulled into some sloppiness on late braking.

Could be the extra 10kph plus lower grip, in spite of a more gentle curve, was enough to be into an extreme situation where the stability control assessed a need to take much more abrupt, less graceful actions.

Whether that is “correct” on its part, this was least bad thing it could do? Yeah, definitely something for Tesla to assess. I agree with “go to the SC” & pass on all this info.

PS Thanks for the Wh/km info. Correct you can’t reset that meter from the steering wheel controls. Instead if you’re traveling at least a few minutes at steady speed on level ground you could later, at safer speed, pull up the 30 min power usage graph.

 

[Magnets!]

I'm with VT_EE above...I'd be surprised that braking at 120mph in a turn was part of the development of model 3. But they are selling cars in Germany so clearly this is something that should be looked at. The brakes aren't overly confidence inspiring at high speed but it could be that the Model 3 brakes just aren't as boosted as much as the BMWs and Audi I have owned and of course the Model 3 is not a lightweight. To the OP, glad you like the Model 3 in general and hope this issue gets some attention from Tesla.

 

[22522]

The car is great at speed. Thank you for helping to get it sorted.

What maybe happening is regenerative braking does not know that it can't handle the power at those speeds until it tries to.

1) what was the state of charge?
2) how cold was it the night before?

The regen needs to vary with speed - i know it does not help range, but there needs to be a safety factor.

With an i3 regen cuts out when you corner to save traction vector on the rear tire contact patch - very important.

No, I don't think it is that... unless regen cutting out confuses the ABS algorithm. Don't know how regen is factored in there. brake heating and coefficient of friction might be changing too fast. I have the same car you have and love it. To brake at that speed you may need the performance brake set...

Don't think that is a may.