Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Traffic Issues

This site may earn commission on affiliate links.

Beta V

Author, Dad, Mentor, Technology Critic
Nov 8, 2017
225
157
Redmond, WA USA
I do not have the $4000 AutoPilot feature installed. I do have AutoDrive which has two modes--manual steering and auto-steering. I have tried to use the first mode (MS) on many occasions and have noticed some pretty disturbing issues. I'm wondering if it's just my Model X or a more pervasive issue.

When I was driving yesterday in local traffic, there were several school zones and a heavily enforced speed limit coming down 165th in Redmond. I used the MS mode to keep me locked on the car in front and at 30 mph. When the car ahead switched lanes, I stayed in my lane and my Model X got confused and slowed down unexpectedly. I had to take over and accelerate through the intersection before being rear-ended by the car behind me.

This is not the first time this has happened. I've had several cases where on MS that the vehicle slows down unexpectedly when the cars ahead move out of the way when I expected my vehicle to continue at the same speed or accelerate to the set speed.

On a related note, my daughter was following me on MS the other day and notice that my brake lights were not coming on as I slowed. Is that a common occurrence?

On AutoDrive (AS) (auto-steer): I drove to the airport last night in very heavy traffic at a very low speed. AS kicked in on request, but even with my hands on the wheel it would drop out. It seems that when I engage AS, the car turns a bit in either direction almost as if it's testing if my hands are there. If I provide too much resistance, it kicks out. If I concentrate on not holding on too tight, it seems to work better but soon kicks out again. Is there a tip or setting I should check?
 
You're getting your terminology all wrong and that's making it difficult to tell what you're talking about.

Full Self-Driving (FSD): An option you can buy that doesn't do anything yet, but promises to someday be capable of full autonomy. Only available on late-2016-and-later Tesla vehicles.

Autopilot: A suite of driver assistance tools composed of...

Autosteer: The car watches the lanes on the road and steers the vehicle to stay between the lines. Autosteer also includes automatic lane change (presently triggered by the driver). It is used in conjunction with...

Adaptive Cruise Control: Radar-and-camera-based cruise control that locks onto the vehicle in front of you and uses it to maintain a safe following distance if the car is driving slower than you.

Summon and Autopark: Using the parking sensors to guide the car forward-and-back, as well as engaging in parallel and perpendicular reverse parking.

If your Model X has Autosteer then it has Autopilot enabled.

As for your concerns...

Following: If the vehicle that is changing lanes is still detected as being in your lane (highlighted in white on the dash), then the Adaptive Cruise Control will continue to maintain speed parity with it. If it slows down, you'll slow. There could be something else, such as a detected obstacle that's not actually an obstacle (bridge, overhead sign, etc), but the recognition system for these has been improving significantly lately.

Brake Lights: You can see in the dash display when your brake lights should be turning on — the little car will match exactly what your car's lights are being told to do. At higher speeds the regenerative breaking isn't as strong at first, so the brake lights don't activate right away. Same as if you were driving a traditional gas vehicle and let off the accelerator — the car would continue forward, but it would immediately begin to decelerate. After a few seconds, the regenerative breaking power will increase and turn on the brake lights. At lower speeds the regenerative braking turns to higher power faster, so the brake lights should come on sooner. If the lights aren't matching what's on the display, you should make an appointment with your local Service Center.

Hands on the wheel: Yep, that's how Autosteer works, to a degree. It's not "testing you," though, it's centering the car in the lane. Odds are good you're not centered; we humans just aren't great about that (as I'm sure you've observed many times in other drivers). The dash display will show you with high accuracy where the car is within the lane. Autosteer detects driver intent based on your resistance to its actions. If you're going along with it, it'll detect you as "present" and continue to do its thing. If you resist too much it assumes you want to take over and disengages. This is by design — if something happens that the car hasn't picked up on, you can grab the wheel and take control without having to manually disable Autosteer.
 
ETA: I'm going to leave this, but the poster above me must have hit post moments before I started typing a reply. My responses aren't really much different than his in terms of content, but they are in terms of writing style, so it could be beneficial to read both if you're still feeling confused.

Regarding your first issue (slowing for a vehicle in the next lane), this is a common occurrence for pretty much all traffic aware cruise control systems. My 2006 Infiniti M45 did it, and it's something you need to be aware of in order to take over with the accelerator just like you did.

Regarding your second issue (brake light not coming on), this is likely when you are using regen and not slowing at some pre-programmed rate. I am guessing this is designed to be no different than driving a manual and letting off of the gas (if regen slows you dow more than letting off the gas in an average manual would, then the brake lights come on). You can actually see whether or not the brake lights are coming on in the dash. You would have an issue if the dash showed them, but they weren't on.

Regarding your third issue (auto-steer kicking off), it sounds like you are gripping the wheel too firmly / fighting it a bit. My impression is that the vehicle is letting you take over because in an emergency you might be more likely to grab the wheel than remember to cancel with the cruise lever. If you're not feeling much resistance, you might change the driving/steering mode (between comfort, standard, and sport). If it feels the same (like practically no resistance) between them, there could be a problem that service would need to look into. Before talking to service, and knowing that you can take over if you need to, you might want to try it on a divided highway at speed to get a better feel for it.
 
You're getting your terminology all wrong and that's making it difficult to tell what you're talking about.

Full Self-Driving (FSD): An option you can buy that doesn't do anything yet, but promises to someday be capable of full autonomy. Only available on late-2016-and-later Tesla vehicles.

Autopilot: A suite of driver assistance tools composed of...

Autosteer: The car watches the lanes on the road and steers the vehicle to stay between the lines. Autosteer also includes automatic lane change (presently triggered by the driver). It is used in conjunction with...

Adaptive Cruise Control: Radar-and-camera-based cruise control that locks onto the vehicle in front of you and uses it to maintain a safe following distance if the car is driving slower than you.

Summon and Autopark: Using the parking sensors to guide the car forward-and-back, as well as engaging in parallel and perpendicular reverse parking.

If your Model X has Autosteer then it has Autopilot enabled.

As for your concerns...

Following: If the vehicle that is changing lanes is still detected as being in your lane (highlighted in white on the dash), then the Adaptive Cruise Control will continue to maintain speed parity with it. If it slows down, you'll slow. There could be something else, such as a detected obstacle that's not actually an obstacle (bridge, overhead sign, etc), but the recognition system for these has been improving significantly lately.

Brake Lights: You can see in the dash display when your brake lights should be turning on — the little car will match exactly what your car's lights are being told to do. At higher speeds the regenerative breaking isn't as strong at first, so the brake lights don't activate right away. Same as if you were driving a traditional gas vehicle and let off the accelerator — the car would continue forward, but it would immediately begin to decelerate. After a few seconds, the regenerative breaking power will increase and turn on the brake lights. At lower speeds the regenerative braking turns to higher power faster, so the brake lights should come on sooner. If the lights aren't matching what's on the display, you should make an appointment with your local Service Center.

Hands on the wheel: Yep, that's how Autosteer works, to a degree. It's not "testing you," though, it's centering the car in the lane. Odds are good you're not centered; we humans just aren't great about that (as I'm sure you've observed many times in other drivers). The dash display will show you with high accuracy where the car is within the lane. Autosteer detects driver intent based on your resistance to its actions. If you're going along with it, it'll detect you as "present" and continue to do its thing. If you resist too much it assumes you want to take over and disengages. This is by design — if something happens that the car hasn't picked up on, you can grab the wheel and take control without having to manually disable Autosteer.


Being a technical writer, I appreciate the clarification of the terms.
As to the Adaptive Cruise Control (ACC), in the aforementioned case, the car in front of me had completely cleared the lane when my vehicle stopped. It's as if the ACC is lagging behind reality by 1500ms. I notice this as well when sitting in traffic at a stop (on ACC) and the car ahead moves off. My vehicle waits about that long (1500ms) before moving off as well--even though there is already a safe distance between us. I attribute this to processor performance--control lag (I spent many years in process control designing systems).

I'll try to learn how to accommodate the eccentricities of the autosteer, but at this point, I don't trust it enough to use it very much.

As to the brake lights, I have no way to know if what's showing up on the dash unless I have someone follow me on a skateboard... ;)

You mention "Autopark." That's my next goal--figure out how to get it to activate. ;) Heading for the documentation.
 
Autopilot and AAC are overly cautious about braking and accelerating. It can't yet judge driver intent right the way we humans can (person is clearly pulling into the other lane, I can continue at this speed and safely clear them), so it's more likely to brake when not needed and sit still for longer than necessary, just to be safe.

Brake lights: Have somebody drive behind you on an open cell phone speaker line and tell you when the lights are turning on? ¯\_(ツ)_/¯

Autopark:
  1. Drive past an open spot at 8mph or slower.
  2. Side sensors will automatically judge the distance between obstacles to determine it's enough space. Cameras aren't involved at this time.
  3. If the car thinks its enough, a [P] will appear in the dash on that side of the car.
  4. Shift into reverse. Reverse camera will appear on the top of the center display, a diagram of the car and detected space on the lower half with a button that says START.
  5. Press START and the car will take over steering, acceleration, braking, and shifting. It'll even center itself in the spot and put itself into park when done.
  6. There's a good chance it will get closer than you're comfortable, so you can press the brake pedal to stop and cancel, but in my experience it has yet to back into another car (the brakes are very touchy, so the moment you touch the pedal the car stops).

Honestly, I've had Autopark fail to see a spot more often than it's failed to park safely and cleanly.
 
  • Like
Reactions: FarmerDave
You can also trigger Autopark by clicking the Park button on the gear lever twice. I believe this is for parking the vehicle in a tight spot where you want to get out before parking (it gives you the option to park forward or reverse). I haven't tried this out, but my experience with the function Derek mentions is not as great as his. That is to say that while I haven't had Autopark do anything I don't want it to do, it looks to me like that is because I typically don't use it. When a parking spot is detected and you don't hit start, it still shows the detected parking spot and your vehicle relative to that spot. I have parked in a few places where, based on my vehicle's final position compared to the detected spot, said detected spot clearly went over a curb or through something else that you wouldn't want to hit.
 
Hi Beta V,

There are two settings that I have not seen you or anyone mention
that could help your car's behavior:

1 for Adaptive cruise control would be the following distance setting...
It is a number set by twisting the end of the cruise control stalk.
The numbers range from 1 to 7.
This is the number of car lengths you want between you and the car ahead of you.
Back in the driver's education days they taught 1 car length for each 10 mph.
If you are set for 6 or 7 which is appropriate for interstate travel, the time
to start from a stoplight following another car may seem to be an eternity.
For local driving a setting of 3 to 5 may be more appropriate.

2 The Regenerative braking setting...
Standard for more braking... slows quicker, returns more energy to the battery, and saves your brakes.
Low for less braking... slows less, less energy returns to the battery, and more wear on the brakes.

A complication for the regenerative braking is the charge level of your battery and the weather...
If your battery has a high level of charge the regenerative braking will be less because the battery
cannot take the "extra" charging.
Another complication is the poor weather we all have been enduring.
While your battery is "cold" defined as 40 degrees F or less the battery will also hold "less"
of a charge from the regenerative braking.
The power meter has yellow dashes beyond 50 Kw means it is regen. restricted. due to temperature.
If the power meter has the yellow dashes at 50 Kw and a yellow warning triangle it will receive even
less charge which means even less braking...

The regenerative braking behavior can also affect your brake lights.

I hope this helps,

Shawn
 
You can also trigger Autopark by clicking the Park button on the gear lever twice. I believe this is for parking the vehicle in a tight spot where you want to get out before parking (it gives you the option to park forward or reverse).

This is Summon, not Autopark.

I haven't tried this out, but my experience with the function Derek mentions is not as great as his. That is to say that while I haven't had Autopark do anything I don't want it to do, it looks to me like that is because I typically don't use it. When a parking spot is detected and you don't hit start, it still shows the detected parking spot and your vehicle relative to that spot. I have parked in a few places where, based on my vehicle's final position compared to the detected spot, said detected spot clearly went over a curb or through something else that you wouldn't want to hit.

Definitely never go into it blind. Look, ensure it's a good spot, watch the cameras and mirrors as it goes.
 
  • Like
Reactions: FarmerDave
For the record: I got my X back and used the double-click on the Park (shift-lever) button to engage this feature, and it says auto-park in the MCU when I do. I also happened to find the summon sensitivity settings and change them before trying this, because summon previously wouldn't put the X in my garage (8ft door). The summon settings may have affected this feature (not sure I've actually used it to try to park the car in my garage before), but then again, even if they did, they may affect all auto-park functions.
 
Autosteer at local streets does not work well and I don't really use it. If you keep an eye on the Autosteer icon, it goes blue and dark even without turning Autosteer on. I think it is a combination of geofencing and line reading that prohibit Autosteer on certain sections of the roads. And it also gets confused at intersection when car in front changes lane or made turns because there are no lines. It works okay if you are by yourself. Also the hand on steering wheel detection system needs a lot of work. If you hands are perfect balance on the wheel at 2 and 10 o'clock position driving in a straight line, it does know your hands are on the wheel. It doesn't detect any torque so it thinks your hands are off. You are better off with an orange wedged AND your hands.