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TACC Question

doggy1

Member
Oct 15, 2019
132
122
Sydney, Australia
I've only had my Model 3 one week and liking it very much. Nearly everything is behaving as expected or per my pre-education about the car.

However, there is one thing which I cannot seem to get right and I am sure it is "finger trouble" on my part.

Hopefully, just about anyone with a bit more experience will be able to set me straight.

I engage TACC by briefly pulling down the right stalk. It works beautifully and I am very impressed. However, I cannot get it to change speed according to the speed limit. For example, I pull down the lever in a 50 area but the car stays at 50km/hr even after I pass into a 60 zone. Same if I start in a 60- it stays at 60 even when the limit changes to 50. In other words, it is maintaining the speed I initially set regardless of entering other speed zones. It is doing a fabulous job of reading the speed signs and also keeping a set distance behind other traffic. Maybe when I pull down the stalk, I need to do it longer? However, even when I touch the speed limit icon, that does not seem to change the behaviour.

So, I am probably not understanding the fine points of TACC and would experience some advice on how to make it change speed according to the speed zone in which the car is driving.
 

atj777

Member
Feb 25, 2020
256
88
Australia
It won't change speeds automatically on entering a different speed zone. You have to move the stick down and hold it for it to change to the new speed.
 
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paulp

Active Member
Jul 23, 2015
3,193
1,598
Adelaide, Australia
It won't change speeds automatically on entering a different speed zone. You have to move the stick down and hold it for it to change to the new speed.
Actually mine does sometimes. Its random though. The frustrating one that isnt random is the new freeway which is 80kmh. The car still thinks its 60kmh, so every signpost is slows down to 60kmh.
I dont think it changes speed below 60kmh though, possibly because its not always signposted. (In SA its 50kmh unless signed otherwise)
 

Shallowal

Member
Aug 31, 2019
162
97
Forster
You can set the speed to what it has read by pushing down on the right stalk for a second or so (ie: a long push).
The car will automatically update its actual speed in some circumstances, but will never go above the speed it was initially set too. eg: on our secondary road, if I set the speed in the 80 zone and then it comes to a 60 zone, it will automatically slow down. It will then increase speed at the end of that 60 zone to the new speed limit. However if that new speed limit is 100 it will only automatically go to 80.
 
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atj777

Member
Feb 25, 2020
256
88
Australia
I don't think mine has every slowed down automatically for me. For example, M4 to Lapstone Hill changes from 110 to 90 km/h. I have my TACC set to +5 so if I don't disengage the TACC, I go up Lapstone Hill at 115 km/h.
 

QBN_PC

Member
Feb 11, 2020
368
422
Queanbeyan
One-push TACC never slows down.

Two-push Autosteer will slow down, but only on general streets and roads. It won't slow down on limited access roads (motorways).

In the US the speed limit and many road rules are barely observed on freeways, but they're strictly enforced on local streets (though it varies greatly depending on what city or county you're in). The AI logic follows that reality, even though it's the opposite here. Over there most enforcement is an officer that just pulled you over, and is standing next to you writing a citation - something you don't really want to do on a freeway & would rather do on any other street. Over here most speed enforcement is through fixed or mobile cameras, with a fine in the mail in a few weeks - revenue you're more likely to raise along a free-flowing motorway.
 

Vostok

Active Member
Jul 1, 2017
1,778
1,889
Sydney
One-push TACC never slows down.
Well my Model 3 did that on the M4 tunnel last week, where I was on TACC and the speed limit is 80, going onto a exit ramp where the speed limit was 60. For the first time I can ever recall, my car slowed down by itself to the new speed limit. However it did not speed up again after the speed limit went back up to 80 - the sign was recognised but the speed stayed at 60.
 

Vostok

Active Member
Jul 1, 2017
1,778
1,889
Sydney
I engage TACC by briefly pulling down the right stalk. It works beautifully and I am very impressed. However, I cannot get it to change speed according to the speed limit.
Another way to do it is to tap the speed limit sign on the UI. If TACC is active, doing this will set your speed to what the sign shows.
 
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Shallowal

Member
Aug 31, 2019
162
97
Forster
Well my Model 3 did that on the M4 tunnel last week, where I was on TACC and the speed limit is 80, going onto a exit ramp where the speed limit was 60. For the first time I can ever recall, my car slowed down by itself to the new speed limit. However it did not speed up again after the speed limit went back up to 80 - the sign was recognised but the speed stayed at 60.
We have a section of road here that is signposted to 80 (just after the 60 zone), but the car never increases speed here. I think it must be using some other mapping info to determine the speed zone.
 

paulp

Active Member
Jul 23, 2015
3,193
1,598
Adelaide, Australia
Actually mine does sometimes. Its random though. The frustrating one that isnt random is the new freeway which is 80kmh. The car still thinks its 60kmh, so every signpost is slows down to 60kmh.
I dont think it changes speed below 60kmh though, possibly because its not always signposted. (In SA its 50kmh unless signed otherwise)
After the last flurry of updates my car no longer slows down as described above when in TACC
 

QBN_PC

Member
Feb 11, 2020
368
422
Queanbeyan
I think it was based on mapping. A few months ago it sometimes slowed down, but if I recall correctly, it was always in places where a road name changed at the same spot as the speed limit changed. Possibly from M4 Motorway to M4 Motorway Off Ramp.

Not that I use the M4 much. Greedy effers! :)

A few updates back they had a major maps update, didn’t they?
 

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