New Brakes Time?

[Kr33m0]

For a few weeks now my 2019 feels like it has "regen" braking! It happens mostly first thing in the morning where the car would slow abruptly when taking the foot of the gas and when lightly braking - causing me to lunge forward a bit. I have just under 26K miles - is it time for new brake pads?

 

[DonD]

Are you going downhill on cruise control when this happens? If so, that's "Smart Cruise Control" at work.

If not, I don't know what the cause is. Good luck. Don

 

[turboAWD]

Are you in sport / comfort mode? Sport / comfort have "engine braking", where it will keep pressure in the trans to add engine braking when you are off throttle, even in the city. If you're not expecting it, you will get that lurching effect, and with cold ATF, it will probably be stronger than warmed up.

Try enabling the "coasting" option (under setup / car menu, IIRC), and driving in smart or eco.

We just did a 1500+ mile roundtrip to Vegas, and using Smart / Eco up and down all those hills helped with the mileage, when you can coast down a hill and the rpm is at 1000.

In sport mode, it would stay in gear, keep the rpm at 1700-2000+ and actively slow you down with engine braking.

 

[Kr33m0]

No cruise control going downhill or anything like that. It's just that I never felt it so much before until now. I am usually in comfort mode mostly. I dont feel it as much when going at the speed limit in either comfort/sport!

 

[Snicklefritz]

if your pads are shot your rotors will be too. you said 'a few weeks' this has been going on. that's plenty of time for shot pads to trash the rotors. if the rotors are fine, along with the pads, and braking is smooth, then no you do not need new brakes.

 

[turboAWD]

No cruise control going downhill or anything like that. It's just that I never felt it so much before until now. I am usually in comfort mode mostly. I dont feel it as much when going at the speed limit in either comfort/sport!

Just note: I'm not talking about cruise either. And it's not THAT noticeable at the speed limit - it's most noticeable at 5-10 mph, if you lightly hit the brakes, and then the trans braking also kicks in.

 

[Thomby]

For a few weeks now my 2019 feels like it has "regen" braking! It happens mostly first thing in the morning where the car would slow abruptly when taking the foot of the gas and when lightly braking - causing me to lunge forward a bit. I have just under 26K miles - is it time for new brake pads?

As you slow to a stop, watch your revs and see if they bounce up a bit at each lurch. It won't be a ton since the 8 speed means close gears, which is why I didn't realize that's what it was (I thought maybe the car was braking harder on my behalf as I approached stopped cars), but there's a good chance you're feeling the car downshifting without disengaging the torque converter.

 

[rpoffen]

No cruise control going downhill or anything like that. It's just that I never felt it so much before until now. I am usually in comfort mode mostly. I dont feel it as much when going at the speed limit in either comfort/sport!

There is adaptive factors in the transmission that might change the behavior over time based on your driving habits and may be your problem The dealer can reset those (but they may come back over time), the Xtools A30D code scanner seems to be able to reset it too.

 

[Snicklefritz]

There is adaptive factors in the transmission that might change the behavior over time based on your driving habits and may be your problem The dealer can reset those (but they may come back over time), the Xtools A30D code scanner seems to be able to reset it too.

I thought that 'learning' your driving style only worked in smart mode.

 

[stoopid]

My trans does an engine brake assist like described. I've had it feel abrupt a couple times, but it's mostly unnoticeable.

 

[RM7]

First of all new brakes is probably a tall order, there's one or two aftermarket brake options, but you are probably better off with just pads instead of totally different/new brakes.

The ZF8spd transmissions can be pretty smart. They will adapt to driving style and conditions. They do not "run away" as easily as older auto trans down hills and such. They will down shift on their own and maintain speed better than older or cheaper ones. I've noticed this with my BMW and other high end autos, while low end ones on rentals I use nearly every month still tend to act "dumb".

 

[D.J.]

Just note: I'm not talking about cruise either. And it's not THAT noticeable at the speed limit - it's most noticeable at 5-10 mph, if you lightly hit the brakes, and then the trans braking also kicks in.

does it do the same in neutral?

if it does not - then the concern i not brake related.

Isolate the issue - is it brakes - or transmission related?

 

[D.J.]

I thought that 'learning' your driving style only worked in smart mode.

smart mode doesn't "learn" anything. It just selects the most correct mode based on the pre-programed algorithm.


To clarify - transmission adaptives work in all drive modes, and normally never need to be reset.

 

[21PanGreyGT]

There is adaptive factors in the transmission that might change the behavior over time based on your driving habits and may be your problem The dealer can reset those (but they may come back over time), the Xtools A30D code scanner seems to be able to reset it too.

Have you used the tool to reset the TCU? Looking for advice on how to use it. I need my TCU reset for being too sluggish which seems to be the opposite of everyone else. All the dealers around me have 2 week wait times for service and would rather do it myself if possible.

 

[D.J.]

The ZF8spd transmissions can be pretty smart.

What car you talking about?