Jerky automatic transmission shifting

[RobertE]

Yea I think it just might be normal. After all it’s a single clutch and not a dual clutch transmission. If you ask me, the aggressive shifts make the car more fun to drive.

 

[Silvermanor]

9000km and I'm starting to notice weird throttle or transmission behavior. For example today I was on the car at half throttle and the car almost felt like it had turbo lag or a slipping transmission for about 5 seconds. Almost like there was no power in the engine. It's really hard to describe but it did not feel normal to me. I'm also noticing jerkier, more inconsistent shifts in comfort mode while putzing around at regular city speeds.

 

[Duox]

Hi all,

I'm having this issue noticably at 1k miles. The most jarring is when the car is downshifting while braking or coasting. The downshifts are so hard to maintain consistent braking, I need to let off the brake entirely, then once shifted but my foot on the brake hard. Consistent braking will just jerk you around.
As an earlier poster said, "they probably calibrated it that way to use the engine as a brake and also get the car in the correct gear for that speed" and also "sometimes it even feels like the car speeds up slightly as you are trying to slow down while the transmission goes though the shift change between gears and loses the engine braking effect," both describe my issue. I'd be fine if this was sport-mode only behavior, but it's just a prevalent in comfort as well.

It sounds like their was an update to the logic that helped fix this: issue SA341. What should I request them to update? And would this had already been fixed on a early 2019 GT1 AWD Stinger? Thanks all!

 

[Marc Collins]

Hi all,

I'm having this issue noticably at 1k miles. The most jarring is when the car is downshifting while braking or coasting. The downshifts are so hard to maintain consistent braking, I need to let off the brake entirely, then once shifted but my foot on the brake hard. Consistent braking will just jerk you around.
As an earlier poster said, "they probably calibrated it that way to use the engine as a brake and also get the car in the correct gear for that speed" and also "sometimes it even feels like the car speeds up slightly as you are trying to slow down while the transmission goes though the shift change between gears and loses the engine braking effect," both describe my issue. I'd be fine if this was sport-mode only behavior, but it's just a prevalent in comfort as well.

It sounds like their was an update to the logic that helped fix this: issue SA341. What should I request them to update? And would this had already been fixed on a early 2019 GT1 AWD Stinger? Thanks all!

The aggressive down-shifting is part of the design of a "sporty" car. Try ECO mode if you want something closer to a traditional American car automatic. Also, as is the case with a manual transmission car that the engineers were trying to mimic, you don't ride the brakes. You take your foot off the gas and let the car/engine slow you until steady application of the brakes is needed to bring the car to a halt. By the time you have let the engine braking do its job, the remainder braking phase should be firm and smooth. If your foot is usually on the gas right up until the moment you need to push the brake pedal to deal with traffic, you aren't driving in a way that the car thinks equals smooth and steady. It reads "spirited" or "aggressive" from those inputs.

The only time I have ever had the car behave as you describe, is if beforehand I have either stabbed the brakes because I wasn't paying attention to traffic closely enough and needed heavy braking, and/or combined that with stabby application of the throttle, either of which signals to the transmission to go into a slightly more aggressive mode (even in Comfort). Before getting any TSB applied, I would try to pay attention to driving and see if the car is behaving as if it had a manual transmission, or if there is something wrong.

The car never speeds up while coasting, but some people get confused because the engine will speed-up and slow-down as it down-shifts to ensure the car is in the right gear if you choose to apply throttle (something older automatics did not do well at all). The surges of braking g-force as each lower gear is engaged might fool people into thinking the car is not continuously decelerating, but it is, just at inconsistent rates--and it's the same experience in a manual transmission car or in a racing car. The goal, as it is in a race car or a manual shifter, is to use the brake pedal the least possible, but when you do use it, it's to more seriously slow the car for an upcoming corner or to come to a stop.

The Stinger (programming) does not perform well with the typical North American "race between stop lights," jerky, stop-and-start driving style. If you try forcing only smooth application of the throttle and brake, just as a test, it might be revealing. And smooth does not mean little. You can drive as aggressively and fast as you want (the car actually works better when you ask it to really go), but ensure the pedal application is smooth and deliberate, not stabby or jerky.

If you want 80% throttle, you have two choices: jab the throttle to 80% or smoothly push it to 80% taking about one second to get there (the time it takes to say "one-one thousand"). When I do the first one, the car sometimes hesitates and feels like it has major turbo lag or some other problem. What is actually happening is the jab is setting the car into emergency alert mode--it pauses to figure out how many gears to drop, curtails the engine rpm so when it figures out what gear to use it there is a proper clutch action to not damage anything, etc. Feels to us like a uncomfortable delay. If I drive the car properly (like a manual), using the accelerator position to go faster or lifting to slow the needed amount (like a mild version of an electric car) and goose the throttle using the smooth but firm method, the car responds instantaneously (even in Comfort mode).

Moving to Sport mode mostly just puts the car into the higher alert state--assuming you already know you want to be more aggressive. It's not providing any different performance. The rate of application and de-application of the pedal forces is a major input into the car's electronic wizardry (that we cannot change), so learning to work with it may be better than getting a reprogramming (that we know from experience with many other cars in the past decade can create as many new issues as it resolves). Remember, just taking your foot off the gas pedal suddenly as opposed to smoothly counts as a mild alert to the car.

Let us know if this easy-to-implement test reveals anything.

 

[Duox]

The aggressive down-shifting is part of the design of a "sporty" car. Try ECO mode if you want something closer to a traditional American car automatic. Also, as is the case with a manual transmission car that the engineers were trying to mimic, you don't ride the brakes. You take your foot off the gas and let the car/engine slow you until steady application of the brakes is needed to bring the car to a halt. By the time you have let the engine braking do its job, the remainder braking phase should be firm and smooth. If your foot is usually on the gas right up until the moment you need to push the brake pedal to deal with traffic, you aren't driving in a way that the car thinks equals smooth and steady. It reads "spirited" or "aggressive" from those inputs.

The only time I have ever had the car behave as you describe, is if beforehand I have either stabbed the brakes because I wasn't paying attention to traffic closely enough and needed heavy braking, and/or combined that with stabby application of the throttle, either of which signals to the transmission to go into a slightly more aggressive mode (even in Comfort). Before getting any TSB applied, I would try to pay attention to driving and see if the car is behaving as if it had a manual transmission, or if there is something wrong.

The car never speeds up while coasting, but some people get confused because the engine will speed-up and slow-down as it down-shifts to ensure the car is in the right gear if you choose to apply throttle (something older automatics did not do well at all). The surges of braking g-force as each lower gear is engaged might fool people into thinking the car is not continuously decelerating, but it is, just at inconsistent rates--and it's the same experience in a manual transmission car or in a racing car. The goal, as it is in a race car or a manual shifter, is to use the brake pedal the least possible, but when you do use it, it's to more seriously slow the car for an upcoming corner or to come to a stop.

The Stinger (programming) does not perform well with the typical North American "race between stop lights," jerky, stop-and-start driving style. If you try forcing only smooth application of the throttle and brake, just as a test, it might be revealing. And smooth does not mean little. You can drive as aggressively and fast as you want (the car actually works better when you ask it to really go), but ensure the pedal application is smooth and deliberate, not stabby or jerky.

If you want 80% throttle, you have two choices: jab the throttle to 80% or smoothly push it to 80% taking about one second to get there (the time it takes to say "one-one thousand"). When I do the first one, the car sometimes hesitates and feels like it has major turbo lag or some other problem. What is actually happening is the jab is setting the car into emergency alert mode--it pauses to figure out how many gears to drop, curtails the engine rpm so when it figures out what gear to use it there is a proper clutch action to not damage anything, etc. Feels to us like a uncomfortable delay. If I drive the car properly (like a manual), using the accelerator position to go faster or lifting to slow the needed amount (like a mild version of an electric car) and goose the throttle using the smooth but firm method, the car responds instantaneously (even in Comfort mode).

Moving to Sport mode mostly just puts the car into the higher alert state--assuming you already know you want to be more aggressive. It's not providing any different performance. The rate of application and de-application of the pedal forces is a major input into the car's electronic wizardry (that we cannot change), so learning to work with it may be better than getting a reprogramming (that we know from experience with many other cars in the past decade can create as many new issues as it resolves). Remember, just taking your foot off the gas pedal suddenly as opposed to smoothly counts as a mild alert to the car.

Let us know if this easy-to-implement test reveals anything.

It's interesting to learn that the car is learning based on my driving characteristics.
So generally I thought I don't do the American style brake slamming. Instead I like to coast to a stop. However, I'm coming from a 98 Camry. That thing would coast all day long without any gas. That's where the jerkiness gets me. I'm used to needing to apply the brake or the car just continues forever.

Im going to go for a drive and report in if smoother braking / less braking, in the spirit of a manual car, works to alleviate what I'm concerned with. Thanks for the response!

 

[Marc Collins]

It's interesting to learn that the car is learning based on my driving characteristics.
So generally I thought I don't do the American style brake slamming. Instead I like to coast to a stop. However, I'm coming from a 98 Camry. That thing would coast all day long without any gas. That's where the jerkiness gets me. I'm used to needing to apply the brake or the car just continues forever.

Im going to go for a drive and report in if smoother braking / less braking, in the spirit of a manual car, works to alleviate what I'm concerned with. Thanks for the response!

One easy trick to remember is that. like an electric car, if you want the Camry float/coast feeling, you have to actually apply/maintain a small amount of throttle. It's the foot off the gas=coast that is the issue. Old Buick's and Camry's taught us bad habits And used more brakes than were necessary. It's a joy to drive in Europe where most cars are manuals and see traffic without the continuous wall of brake lights (that ultimately dulls our sensation of them, because they are essentially on all the time or flashing on and off so frequently, they no longer mean anything).

I might be wrong about this, but it will still be worth a try to see if you can manipulate the car's behaviour. Also, sometimes you have to drive in a certain way for a period of time before the car will relent and change modes, so be patient

 

[Duox]

So I drove around a bit mindful of aggressive braking. It did seem to be less aggressive with shifting impulse. The main issue of increased deceleration in the 30mph down to 20mph is still prevalent. It really could be I just drive in terrible aggressive start stop traffic where the car has "learned" it should do this with the engine to compensate for my brakes. I'll try be more conscious of my braking and to be mindful that it's just my engine trying to help out. I just wish it was more gradually applied throughout and not just within that speed range but that can be just the sport car DNA.

 

[Marc Collins]

So I drove around a bit mindful of aggressive braking. It did seem to be less aggressive with shifting impulse. The main issue of increased deceleration in the 30mph down to 20mph is still prevalent. It really could be I just drive in terrible aggressive start stop traffic where the car has "learned" it should do this with the engine to compensate for my brakes. I'll try be more conscious of my braking and to be mindful that it's just my engine trying to help out. I just wish it was more gradually applied throughout and not just within that speed range but that can be just the sport car DNA.

It's definitely not a linear "helping force," just as in a manual. Depending on the gaps between the gear ratios and when you choose to downshift, you'll get more or less engine breaking effect. In this case, the car is making the decisions!!

Another good thing to "play with" is manual mode. Try doing the down-shifting yourself sometimes. You can do it more quickly or more slowly than the car would to compare. Same with up-shifting.

 

[Duox]

So if you wait later to downshift while slowing down, you get more engine brake? If you know of any good resources that explains engine braking with a manual, I'd appreciate it!

 

[Marc Collins]

So if you wait later to downshift while slowing down, you get more engine brake? If you know of any good resources that explains engine braking with a manual, I'd appreciate it!

Yes. Try it out yourself in manual mode and you will get it very quickly. No clutch to worry about, so you can't hurt anything.

The old-style "slush box" automatics went into a coast mode when you lifted off the accelerator--typically remaining in (a) high gear until you came right to a stop. Interestingly, the 2019 Stinger has an option to do this that can be enabled as part of ECO mode (I believe it is only functional in ECO, but I have a 2018, so don't know). Do you have a 2019? Find the option in the car settings menu for Coasting Neutral Control if you do! This lets you have a Camry when you prefer it with a simple twist of the drive mode dial.

 

[Stinger @ JSC]

Yes. Try it out yourself in manual mode and you will get it very quickly. No clutch to worry about, so you can't hurt anything.

The old-style "slush box" automatics went into a coast mode when you lifted off the accelerator--typically remaining in (a) high gear until you came right to a stop. Interestingly, the 2019 Stinger has an option to do this that can be enabled as part of ECO mode (I believe it is only functional in ECO, but I have a 2018, so don't know). Do you have a 2019? Find the option in the car settings menu for Coasting Neutral Control if you do! This lets you have a Camry when you prefer it with a simple twist of the drive mode dial.

I have a 2019 GT and the Coast option works in Smart mode too but you have to be going 40+ MPH.

 

[Marc Collins]

I have a 2019 GT and the Coast option works in Smart mode too but you have to be going 40+ MPH.

Thanks for info! Do you use it? How do you like it?

It sounds bad if the car free wheels down to 40 mph and then switches to fairy aggressive downshifting after that! If this mode is activated, does it calm the down-shifting at lower speeds, too, or is it just the same as the ECO mode?

 

[Stinger @ JSC]

Thanks for info! Do you use it? How do you like it?

It sounds bad if the car free wheels down to 40 mph and then switches to fairy aggressive downshifting after that! If this mode is activated, does it calm the down-shifting at lower speeds, too, or is it just the same as the ECO mode?

I usual use it on a highway, freeway after going over an overpass and existing. It works pretty good and smooth but one thing I think is odd, if you use your blinker to change lanes it will rengage the trans. I haven't used ECO mode yet, I use SMART mode instead.

 

[Marc Collins]

I usual use it on a highway, freeway after going over an overpass and existing. It works pretty good and smooth but one thing I think is odd, if you use your blinker to change lanes it will rengage the trans. I haven't used ECO mode yet, I use SMART mode instead.

I thought it was a setting in the menu that turned on or off the behaviour? How can you activate it just when you want to use it (e.g., as you mention above at a highway exit)?

 

[Stinger @ JSC]

I thought it was a setting in the menu that turned on or off the behaviour? How can you activate it just when you want to use it (e.g., as you mention above at a highway exit)?

It only works in ECO and SMART modes. I thought I put that in my OP. If not, sorry about that.

 

[Marc Collins]

It only works in ECO and SMART modes. I thought I put that in my OP. If not, sorry about that.

Yes, so it works at all times above 40 mph if it is active (in ECO or SMART)? Your comment about usually using it on a freeway exit made me think you were suggesting it was a choice of when/where you used it above 40 mph. Maybe you meant that's where you notice it regularly?

 

[Stinger @ JSC]

Yes, so it works at all times above 40 mph if it is active (in ECO or SMART)? Your comment about usually using it on a freeway exit made me think you were suggesting it was a choice of when/where you used it above 40 mph. Maybe you meant that's where you notice it regularly?

Well, I guess in a way you can choose when/where you use it. Just turn the drive mode knob to the left once or twice.

 

[westcoastGT]

The rough shift issue just started with mine yesterday , only upshifts in regular or manual , really hard shifts and the engine light has come on now .......................downshifts are fine . I'll take it in this week .

 

[Revvdmedia]

The rough shift issue just started with mine yesterday , only upshifts in regular or manual , really hard shifts and the engine light has come on now .......................downshifts are fine . I'll take it in this week .

Interested to see what the issue is, especially since it triggered your MIL (engine light).

Mine has had rough upshifts (third to fourth) mostly when cold since new, every mode except sport and practically never when manually shifting. I feel like mine is a programming glitch but the genius dealer says rough shifts are normal when cold...not that rough!

Honestly I'm just gonna let it blow out fourth gear if they're not going to do anything about it, then they can replace the whole trans under warranty. If it doesn't break then I guess it wasn't a problem.

 

[cncBilly]

Yes. Try it out yourself in manual mode and you will get it very quickly. No clutch to worry about, so you can't hurt anything.

The old-style "slush box" automatics went into a coast mode when you lifted off the accelerator--typically remaining in (a) high gear until you came right to a stop. Interestingly, the 2019 Stinger has an option to do this that can be enabled as part of ECO mode (I believe it is only functional in ECO, but I have a 2018, so don't know). Do you have a 2019? Find the option in the car settings menu for Coasting Neutral Control if you do! This lets you have a Camry when you prefer it with a simple twist of the drive mode dial.

Mine does it in eco and smart but I don't need to get going 40mph. If I'm on a grade and let go of the gas coast will engage. I turned that feature on and played with it the other day.