TACC resets to current speed when AutoPilot is overridden

TACC resets to current speed when AutoPilot is overridden

I've got a problem with the latest AutoPilot.
If I'm going well below the TACC-set speed limit (because of a vehicle in front of me), and I force the steering wheel to change to a faster lane causing lane-keeping to disengage, the TACC-set speed limit resets itself to my actual current speed.

This is a significant safety issue because I'm changing lanes to a faster lane, and the car (because of the now lower reset TACC speed) won't accelerate on its own.

Tesla Service Center's response:
Determined per engineering article that this is normal operation as of the latest firmware.

NKYTA | March 1, 2019

Bollux on “safety issue”.


Boonedocks | March 1, 2019

Many of us reported that to Tesla and discussed here last year. It is indeed a “negative” improvement.

NKYTA | March 1, 2019

@Boon, did you RTFM before??

Sorry for the snark, but I got to drive my wife’s 3 on NOAp for a couple hundred miles. It ain’t that hard to figure out.

Sure, it isn’t all intuitive, but actually, it is. If I want to merge faster, I’d better have scrolled my right scroll wheel up.

Some learn, some don’t.

redacted | March 2, 2019

Yeah, sucky feature, probably added for lawyers.

p.c.mcavoy | March 2, 2019

@NKYTA - I agree that I don't see this as a safety issue, but what has caused some owners to complain about this is the change in how the feature performs.

AP functionality for multiple years had been that when you manually disengaged autosteer by taking control of the wheel the set speed for the TACC function remained unchanged. This was true even if you were going slower then your set speed. Common example was a passing maneuver where you were slowed behind a car in traffic, lane on your left clears, and you use the wheel to now pass. Car previously would speed up to your set point where now the TACC set point automatically gets reset to your current speed.

For someone like myself that has AP1 that difference was noticeable. Now have I gotten all wound up about it? No.

And for making snarky RTFM comment, I had read the manual, was very well aware of the performance, which is why the change in functionality caught me by surprise a time or two given there was no mention of the change to prior functionality in any release notes that came with my vehicle. As for reading updates to the manual, that actually isn't very useful to me now as there has been no update to a true AP1 manual that would describe to me the functionality of my vehicle given the manuals that Tesla pushes to my owner account are all for latest hardware specific cars.

That's where at some point Tesla does need to realize what it really means to support multiple generation of products and the need for configuration specific owner/service material. I've worked for many years for a company that supports equipment in the commercial vehicle arena where I've simultaneously had to support multiple generations of the same product, with very different functionality at the same time. If as a customer I only had the documentation for the latest generation it would have been a total disaster for me to have figured out what was going on.

Boonedocks | March 2, 2019

@NKYTA it has absolutely nothing to do with the FM...

Silver2K | March 2, 2019

I agree with the OP. It's definitely a safety issue for those that don't realize the updated feature.

Boonedocks | March 2, 2019

Even though most of us actually realize the “feature” it was one of those things, like he rear view camera, that was better before they “fixed” it. Hopefully their will revert back to the original behavior

EVRider | March 2, 2019

I also like the old behavior better. I don’t see any benefit to having the TACC set speed changed if either you or the car disengages Autosteer, and whenever that happens I have to restore the set speed to what I want.

NKYTA | March 2, 2019

Ok, ok, fair enough. I’d not driven the previous version.

I’ll just say that I was doing my best to let the 3 drive. Mad Max was engaged and I just put the turn signal on.

But, I will add, if you really want FSD, how many edge cases do you want Tesla to solve to make switching between the car driving and the human driving to make it seamless??

When in doubt, touch the brake and take over.

Is it just me, or do reflectors vs indents in the roadway make a huge difference in auto lane keeping?

murphyS90D | March 2, 2019

If the reflector is not submerged below the surface of the road it will be gone the next time a snow plow goes by.

One summer my township made a big deal of installing blue reflectors in the center of the road by each fire plug so the fire truck driver could see where the fire plug was before he got there. That winter the snow plows removed all of them. They now have a 3 foot high pole attached to each fire plug.

Ddowns2050 | March 2, 2019

It was a safety issue the first few times this happened. Now that I realize it is going to do this I can accelerate but it is still a pain and inconvenient to do it. I never saw anything in the release notes about this change either.

vpoz | March 5, 2019

Having done my first reasonably long drive since this appeared I have to agree it’s a bit of a safety issue.. you have no real idea of what your cruise speed is set to if you need to take over steering. This results in an extra eyes off road look down to see cruise set speed, plus extra interventions to push the cruise speed back to where you wanted it, all at a time when you really want to have your eyes on the road because you are usually in a position where you are overtaking but the car is going unexpectedly slower than you initially set cruise speed.
Let’s be honest, this change is not a feature, it’s been a software team mistake.

hammer @OR-US | March 5, 2019

This is annoying change. I first noticed it on my 3 and thought it was an AP2 thing but I just got back from a road trip and my AP1 S is doing it also. The old way is better.

Boonedocks | March 5, 2019

Hopefully, as with the rear view camera display on the MCU, Tesla will fix this and revert back to the previous way it operated before they broke it.