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Well, this is interesting, because the intersection that causes me the most trouble has a steep downgrade at a T intersection with a busy two-lane highway.
There is a stop sign for an at-grade train track crossing, then immediately a steep incline down to the highway and another stop sign about 100 feet from the first. There is a relatively unobstructed view for a half mile or so in either direction on the highway, but often lots of traffic including trucks. It is a designated truck route. This US highway has been trying to kill me at one place or another along its route since I was a teenager. It is persistent.
I'm always hard on the brakes approaching the intersection, because of the incline, and the hesitation is the worst if I accelerate onto the highway without coming to a complete stop at the second stop sign. But it still hesitates even if I'm not rolling at all.
I do not have any brake hold feature active, that I'm aware of, and I never left foot brake. Dunno.
The hill holder is not something you turn off and on. It is a feature of the ZF transmission Acura uses. It works going uphill or downhill.
Since my suggestion didn't seem to apply to you. I was curious if other cars using the ZF transmission have reported any problem with a 1 to 2 second hesitation upon acceleration after braking to see if there are others with ZF-transmissioned cars that found solutions other than the one that worked for me.. The Porsche Panamera has a ZF transmission. Their forum has three reports of 1-2 second delays in throttle response delay. Unfortunately, all were traced to the left-foot braking practice with a ZF-transmission having the hill holder feature so they don't apply to you. In all cases the owners were so frustrated because the problem was real, but Porsche Service couldn't replicate it.
I complained this to the dealer at vehicle delivery. They ordered a replacement part then when I dropped my vehicle off the service advisor said the gaps is normal. He even went as far as taking pictures of several RDX in the shop with the same gaps. So he did not replace the rear weather strip. According to dealer this is by design to allow expansion during hot weather. I think it’s BS. The ugly gaps is not in the marketing brochures because Acura knew they are ugly. This is just unacceptable.
the dealer is not telling you the truth. My dealership advisor ordered the new seal and it fits snugly with no ugly gap. I went to the lot and took some pictures of their RDXs on the lot myself, no gap in 50%, gap in the others. The gap is not normal and I agree with you, unacceptable, press the issue with US Acura corporate or change dealerships
The hill holder is not something you turn off and on. It is a feature of the ZF transmission Acura uses. It works going uphill or downhill.
Since my suggestion didn't seem to apply to you. I was curious if other cars using the ZF transmission have reported any problem with a 1 to 2 second hesitation upon acceleration after braking to see if there are others with ZF-transmissioned cars that found solutions other than the one that worked for me.. The Porsche Panamera has a ZF transmission. Their forum has three reports of 1-2 second delays in throttle response delay. Unfortunately, all were traced to the left-foot braking practice with a ZF-transmission having the hill holder feature so they don't apply to you. In all cases the owners were so frustrated because the problem was real, but Porsche Service couldn't replicate it.
Good luck!
Unlike some other current Acura models, 3rd-gen RDX doesn't use a ZF transmission. It uses the Honda 10-speed planetary gear transmission. But the Honda transmission's controller may have a hill-hold feature. <edit> Apparently, it has "hill start assist", whatever that means.
Also, it's possible the powertrain controller is programmed to protect the transmission from damage if drivers use ( or abuse ) the brake launch technique. That's left-foot brake along with accelerator to wind up the torque converter before launch from a standing start.
I complained this to the dealer at vehicle delivery. They ordered a replacement part then when I dropped my vehicle off the service advisor said the gaps is normal. He even went as far as taking pictures of several RDX in the shop with the same gaps. So he did not replace the rear weather strip. According to dealer this is by design to allow expansion during hot weather. I think it’s BS. The ugly gaps is not in the marketing brochures because Acura knew they are ugly. This is just unacceptable.
Curious, did you see this gap in the showroom car? I think people really don’t take vehicle delivery seriously. The excitement and emotions take over. You can absolute deny to take delivery if you see something you don’t like. The dealer will make promises to fix it but it’s not 100% guarantee.
As I said, every case is different. In my case the 1 -to - 2 second delay was absolutely caused by the left foot braking. I can reproduce the problem any time I want, just be going back to left foot braking. I'm sorry that doesn't seem to be your problem. And just as you experienced, it happens most when I am pulling out onto cross traffic and has almost caused several accidents. The road by my house is a private road with a steep incline at the intersection with the main road. it has a limited line-of-sight, so when it looks clear, you have to accelerate fast. Also,at that intersection, i would hold my foot on the brake to keep from rolling backward. and for a fraction of a second press the gas while the foot was on the brake. The hesitation was the WORST at this intersection.(And it is NOT that the car is being held by the brake, the engine RPM never even attempts to rise.) When I stopped using the left foot to hold the brake, the problem disappeared. I can replicate it any time by returning to the practice of using left foot braking. That to me is as much proof of the cause as I need to know what caused MY problem. Obviously from what you say, it is not your problem.
The only suggestion I have is since my problem occurs ONLY on my cars that have the hill-holder feature, that feature is somehow sending a signal that the hill holder is active and not to accelerate until your depressing the accelerator more, takes precedence. Good luck on finding your problem.
I don't understand why left foot braking would cause more hesitation than right foot braking? Are you applying more/less pressure with the left foot when using it to brake? I don't get how the vehicle would know which foot you use to brake. Maybe it's because you feel there is less time between braking and acceleration? Not trying to disprove you at all, but I have noticed zero difference using either my left or right foot to brake. Even though using the left foot makes the transition slightly faster, which is the only thing I can assume you are experiencing.
I don't understand why left foot braking would cause more hesitation than right foot braking? Are you applying more/less pressure with the left foot when using it to brake? I don't get how the vehicle would know which foot you use to brake. Maybe it's because you feel there is less time between braking and acceleration? Not trying to disprove you at all, but I have noticed zero difference using either my left or right foot to brake. Even though using the left foot makes the transition slightly faster, which is the only thing I can assume you are experiencing.
Of course the system doesn't know which foot is pushing any pedal, but if you get in the habit of pushing BOTH the accelerator and brake pedals simultaneously it will know about that. Or resting your foot on the brake pedal. Even a faster transition may have an impact.
According to ECU ( "chip" ) tuners like Hondata and K-tuner, this delay is related to "torque management". In other words the computer is protecting some component(s) from excessive torque. Search the threads in "Performance" for more info. I wouldn't be the least bit surprised if it is programmed to defeat or discourage brake launching, which is a bit obnoxious in an allegedly performance oriented vehicle. ( Disclaimer: I've never "chipped" a car and I don't plan to for a daily driver ).
But although I am loathe to admit my wife is right about something, I do find that temporarily putting the thing in "Sport+" dynamic mode reduces the effective delay at the most troublesome intersection in my daily travels. But I never leave it in that mode for routine driving. YMMV
Of course the system doesn't know which foot is pushing any pedal, but if you get in the habit of pushing BOTH the accelerator and brake pedals simultaneously it will know about that. Or resting your foot on the brake pedal. Even a faster transition may have an impact.
According to ECU ( "chip" ) tuners like Hondata and K-tuner, this delay is related to "torque management". In other words the computer is protecting some component(s) from excessive torque. Search the threads in "Performance" for more info. I wouldn't be the least bit surprised if it is programmed to defeat or discourage brake launching, which is a bit obnoxious in an allegedly performance oriented vehicle. ( Disclaimer: I've never "chipped" a car and I don't plan to for a daily driver ).
But although I am loathe to admit my wife is right about something, I do find that temporarily putting the thing in "Sport+" dynamic mode reduces the effective delay at the most troublesome intersection in my daily travels. But I never leave it in that mode for routine driving. YMMV
Yes it's been mentioned several times that the issue is something related to protecting components from torque, no new info there. I understand what you are saying about having both feet on brake/accelerator or having a faster time between the 2, but that hasn't made any difference at all in my experience. The Sport+ mode has made exactly ZERO difference in the hesitation, you will note many users in this thread have also said as much. Possibly it may be a difference in your vehicle versus others, maybe a different build date with different programming, we can only guess at this point. I'm in NJ and would be highly curious for us to swap cars for a few minutes and see if there are any seat of the pants differences between the 2.
It may not be the same set of conditions that provokes a delay in all cases. ( And it may require different methods to mitigate, if possible ).
For instance, I doubt delay in "kick down" acceleration on the highway has anything to do with the delay some of us notice accelerating from a stop or near stop.
And attempting to accelerate ( forward ) rapidly after coming to a near stop on a 10-15% downgrade may be a somewhat unique set of conditions.
I do notice the "hill assist" feature holding the vehicle when I move my foot from the brake pedal to the accelerator to drive up my steep driveway, after I get the mail. But AFAIK that feature "shouldn't" be active unless I'm trying to accelerate in reverse on a downgrade. Whether it IS active is a different question.
No plans to drive from WI to NJ anytime soon, sorry. Your weather probably sucks as much as mine right now.
FWIW, my Advance is a very early build, 5/18. I would think it would be more pathological than later builds, if anything, but who knows. AFAIK it's not uncommon for there to be running changes in firmware.
None of my comments should be construed as an attempt to deny the existence of the defect. But I have little faith in Acura to resolve the issue in a timely manner, especially for vehicles already sold, and I'm not yet ready to dump the thing. So I'm left with trying methods of operation to mitigate the defect. Good luck with yours.
It may not be the same set of conditions that provokes a delay in all cases. ( And it may require different methods to mitigate, if possible ).
For instance, I doubt delay in "kick down" acceleration on the highway has anything to do with the delay some of us notice accelerating from a stop or near stop.
And attempting to accelerate ( forward ) rapidly after coming to a near stop on a 10-15% downgrade may be a somewhat unique set of conditions.
I do notice the "hill assist" feature holding the vehicle when I move my foot from the brake pedal to the accelerator to drive up my steep driveway, after I get the mail. But AFAIK that feature "shouldn't" be active unless I'm trying to accelerate in reverse on a downgrade. Whether it IS active is a different question.
No plans to drive from WI to NJ anytime soon, sorry. Your weather probably sucks as much as mine right now.
FWIW, my Advance is a very early build, 5/18. I would think it would be more pathological than later builds, if anything, but who knows. AFAIK it's not uncommon for there to be running changes in firmware.
None of my comments should be construed as an attempt to deny the existence of the defect. But I have little faith in Acura to resolve the issue in a timely manner, especially for vehicles already sold, and I'm not yet ready to dump the thing. So I'm left with trying methods of operation to mitigate the defect. Good luck with yours.
The delay that is referenced in this thread is very specific, it's not kick down acceleration, doesn't change with grade, isn't associated with hill assist, etc. It's specifically when applying the brake to a near stop, then without the vehicle stopping rapidly pressing on the accelerator. It doesn't matter if you press hard or soft on the accelerator, the vehicle will sit there and do absolutely nothing for a solid 1-2 seconds, pressing harder will just make it jerk forward more forcefully when the trans does finally engage. That's why it's so dangerous for things like yields, exiting out of parking onto a highway, roundabouts, traffic situations, etc., you are literally without any power at all for those 1-2 seconds, which can be an eternity with fast moving traffic. In my 30+ years of driving a lot of different vehicles I've never experienced such a bad lag, although this is my first (and last) Honda/Acura vehicle.
The delay that is referenced in this thread is very specific, it's not kick down acceleration, doesn't change with grade, isn't associated with hill assist, etc. It's specifically when applying the brake to a near stop, then without the vehicle stopping rapidly pressing on the accelerator. It doesn't matter if you press hard or soft on the accelerator, the vehicle will sit there and do absolutely nothing for a solid 1-2 seconds, pressing harder will just make it jerk forward more forcefully when the trans does finally engage. That's why it's so dangerous for things like yields, exiting out of parking onto a highway, roundabouts, traffic situations, etc., you are literally without any power at all for those 1-2 seconds, which can be an eternity with fast moving traffic. In my 30+ years of driving a lot of different vehicles I've never experienced such a bad lag, although this is my first (and last) Honda/Acura vehicle.
Make that the delay that YOU are referencing in this thread. It's a long thread. But thank you for starting it.
Make that the delay that YOU are referencing in this thread. It's a long thread. But thank you for starting it.
Correction make that the delay that MOST are referencing in this thread. I’ve been following it and that seems to be the case, although there will always be posters who talk about something else. That’s why posters saying things like “my wife solved the issue” doesn’t help, especially when that persons issue isn’t even what the thread is about.
Correction make that the delay that MOST are referencing in this thread. I’ve been following it and that seems to be the case, although there will always be posters who talk about something else. That’s why posters saying things like “my wife solved the issue” doesn’t help, especially when that persons issue isn’t even what the thread is about.
Strange. I thought I was talking about hesitation upon reaccelerating after braking to a near stop.
And I have made no claim to have "solved" anything, although I personally have found "the wife's method" ( AKA twist the Big Chrome Knob ) to be helpful in some circumstances.
I'm really not sure what you are looking for here.
IMO unless and until Acura releases a software update for the drivetrain controller, there will be no definitive solution. Head over to MDXers or Piloteers and see how long a similar discussion about the ZF 9HP transmission went on.
Spoiler: it's not clear that it ever got solved for existing owners, but there were changes to subsequent model years that seem to have mitigated some of the thing's worst behavior. I still wouldn't buy another Honda or Acura with that transmission. Call it PTSD.
I have posted this before, and tested over and over. Pull the right paddle just before you really need to get out of dodge quickly. Don’t hold it, just tap it.
I have posted this before, and tested over and over. Pull the right paddle just before you really need to get out of dodge quickly. Don’t hold it, just tap it.
So let's call that "The Funz Method". And I agree it helps sometimes, but I think you need to do it within a few seconds of your demand for acceleration.
But none of this would be necessary if Acura got its shit together and got the software worked out, so we could just drive the car and let the AUTOMATIC transmission do its thing. You know, like every darn automatic transmission on the planet until a few years ago.
so let's call that "the funz method". And i agree it helps sometimes, but i think you need to do it within a few seconds of your demand for acceleration.
But none of this would be necessary if acura got its shit together and got the software worked out, so we could just drive the car and let the automatic transmission do its thing. You know, like every darn automatic transmission on the planet until a few years ago.
I have posted this before, and tested over and over. Pull the right paddle just before you really need to get out of dodge quickly. Don’t hold it, just tap it.
why not the left paddle to get the tranny to downshift? Wouldn’t that be better?
So let's call that "The Funz Method". And I agree it helps sometimes, but I think you need to do it within a few seconds of your demand for acceleration.
But none of this would be necessary if Acura got its shit together and got the software worked out, so we could just drive the car and let the AUTOMATIC transmission do its thing. You know, like every darn automatic transmission on the planet until a few years ago.
maybe it can not be fixed with software and needs newly designed tranny
maybe it can not be fixed with software and needs newly designed tranny
Possible, but AFAIK the transmission is working OK in other applications, like Accord.
I do wonder about the torque capacity, since they bumped up the engine output for RDX. I don't think the AT is slipping, but the ECU may be dialing back output to protect it. If the transmission were more robust, that wouldn't be necessary.
why not the left paddle to get the tranny to downshift? Wouldn’t that be better?
You are telling the tranny to 'respond' in some way. It is just an input to a computer with software.
You are giving it an input, you just want to get it out of its 'looking' cycle and get its' attention.
The 'input' (paddle) appears to get the ECU out of its 'delay' loop and then shifts or responds properly. If you can, try it, and see if it helps.
I write software for a living and use/write code that does just this. Sensors publish data, and subscribers (ECU) receive data. The bus is either overwhelmed, or the ECU needs to react faster, with different priorities from a stop or sliding start.
As for why not the left paddle? you can, but then it will stay in the gear as long as it can. The right paddle is still an input, but will not get you stuck in a gear.
Yes, you need to do it just before you hit the gas. I will play around and see how long I can wait to hit the gas after hitting the paddle, and see some kind of positive effect.
You are telling the tranny to 'respond' in some way. It is just an input to a computer with software.
You are giving it an input, you just want to get it out of its 'looking' cycle and get its' attention.
The 'input' (paddle) appears to get the ECU out of its 'delay' loop and then shifts or responds properly. If you can, try it, and see if it helps.
I write software for a living and use/write code that does just this. Sensors publish data, and subscribers (ECU) receive data. The bus is either overwhelmed, or the ECU needs to react faster, with different priorities from a stop or sliding start.
As for why not the left paddle? you can, but then it will stay in the gear as long as it can. The right paddle is still an input, but will not get you stuck in a gear.
Yes, you need to do it just before you hit the gas. I will play around and see how long I can wait to hit the gas after hitting the paddle, and see some kind of positive effect.
Thanks for the explanation, again. I now recall you've explained this before. I'm wondering how soon after the paddle tap can you press the gas.
I am going to assume that after you hit the paddle, and as soon as you see the "D" change to a "D10" to indicate the gear you are in then you can stomp on the gas. Do you expect that should work, or is more delay needed?
Your last post discussed increasing the time between paddle and peddle. I'm more interested in the shortest time that will be effective.
Thanks for the explanation, again. I now recall you've explained this before. I'm wondering how soon after the paddle tap can you press the gas.
I am going to assume that after you hit the paddle, and as soon as you see the "D" change to a "D10" to indicate the gear you are in then you can stomp on the gas. Do you expect that should work, or is more delay needed?
Your last post discussed increasing the time between paddle and peddle. I'm more interested in the shortest time that will be effective.
have not tested the shortest time between pad and ped.
All I know is of I tap a pad just before I ped, it reacts pretty well.
If anything, tapping the downshift paddle may not yield any input to the transmission because you might not be able to go from D2 to D1 depending on your speed or rpms when coming to stop like this where you want to stop and coast for a few seconds before mashing on the accelerator like you would normally do crossing traffic. But generally you should always be able to upshift in this situation so tapping the right paddle makes sense to me. Going to try it out on my next drive today.
Its sucks that such a great and capable car is hamstrung like this with the most basic of functions, and yes it is a huge safety concern for me as well. I like said months ago in this thread, i can't believe the Engineers that developed this car and tested this car would accept this kind of delay from the engine/transmission. I bought this RDX, because A. I used to have a RSX-S 15 years ago and loved it (except for the oil burning issue of the early K-20 engine) and I watched all of the great reviews on youtube, and none of them spoke of this issue. When I buying the car I was also looking at a used Porsche Macan-S, which was just bit more expensive than the 1 year old RDX I have. I settled on the RDX for pricing and larger backseat and cargo room and reliability. I really like the car, but everytime I experience this delay i say to myself, bet a MACAN-S doesn't sit and think about accelerating.
Just had my first service (9,000 miles). I’ve noticed the same hesitation, asked if there might be a transmission software update (no such luck). Fingers crossed they figure this out.
I notice some hesitation as well. Nowhere near as bad as my Mazda 3, though. I could count a full 1.5 seconds from pressing the accelerator to the car moving from a stop. It could be downright dangerous, so I got in the habit of putting it into Sport mode when I had to start moving with any aggression. In the Mazda, I think engineers achieved great gas mileage by making the standard mode in the car deliver overly sluggish accelerator response, and the trans keeps the gear as high as possible while cruising. Zoom zoom? Not so much.
I notice some hesitation as well. Nowhere near as bad as my Mazda 3, though. I could count a full 1.5 seconds from pressing the accelerator to the car moving from a stop. It could be downright dangerous, so I got in the habit of putting it into Sport mode when I had to start moving with any aggression. In the Mazda, I think engineers achieved great gas mileage by making the standard mode in the car deliver overly sluggish accelerator response, and the trans keeps the gear as high as possible while cruising. Zoom zoom? Not so much.
I know this hesitations seems like eternity, but I doubt its indeed 1.5sec, maybe 0.5-0.8sec
I'd say it's variable. I have noticed that it is extremely sensitive to tire slip. In conditions where I accelerate and turn from a snowy side street onto clear highway, it may take a full one-potato-two-potato-three-potato before the darn thing decides it's OK to put down some power.
This is in "Sport Mode" with SH-AWD and snow tires, and it's not like there is any danger of spinning out into a ditch on dry highway.
I haven't yet tried turning off the vehicle stability assist (VSA), which apparently includes traction control/ engine throttling "features" on this vehicle. But it makes me wonder how many nanny systems need to be turned off to make this "performance car" actually perform.
VSA® helps to stabilize the vehicle during cornering if the vehicle turns more or less than what was intended. It also assists in maintaining traction on slippery surfaces. It does so by regulating engine output and selectively applying the brakes.
I know this hesitations seems like eternity, but I doubt its indeed 1.5sec, maybe 0.5-0.8sec
True. Probably more like the timeframes you said. The Mazda actually felt like 5 seconds after I test drove a Tesla Model 3 performance. Instant torque and acceleration that hurts your eyeballs.
I know this hesitations seems like eternity, but I doubt its indeed 1.5sec, maybe 0.5-0.8sec
Doesn't matter whether it's 1.5 or 0.5-0.8, which are all probably speculations and unscientific measurement. What matter is that it is whole heartily felt and driving experience impacted.
Doesn't matter whether it's 1.5 or 0.5-0.8, which are all probably speculations and unscientific measurement. What matter is that it is whole heartily felt and driving experience impacted.
agree, you can learn how to manage it, but would be nice if its fixed, given that its not fixed for so long, they probably cant fix it with software
I have been using the 'brake Hold' function alot the past week, and find that my launch is much better with the Hold on. I also don't like the idle stop to be on, and forgot to turn it off that morning. I was on Hold at a light, the idle stop kicked on and stopped the engine, then 30 seconds later started the car back up, while still on Hold, which is the proper functionality. But when it started back up, the car moved forward, and I used the brake to stop . maybe a foot or two, hard to say since I applied the brakes quickly. Thats bad! So I continue being a 'idle stop trainee' everytime I get into the vehicle to ensure that button gets pushed...
agree, you can learn how to manage it, but would be nice if its fixed, given that its not fixed for so long, they probably cant fix it with software
I partially disagree, you can't really learn to manage it in many situations because sometimes things come up and you don't have time to think. In my personal experience it is at least a second, possibly a hair more, although my "scientific" method is to count 1-Mississippi and the throttle kicks in very slightly after I finish a count of 1. Would be interesting for someone to do a more scientific test, but there is probably a lot of variance, for example how long it takes me to take my foot off the brake and put it on the gas.
I partially disagree, you can't really learn to manage it in many situations because sometimes things come up and you don't have time to think. In my personal experience it is at least a second, possibly a hair more, although my "scientific" method is to count 1-Mississippi and the throttle kicks in very slightly after I finish a count of 1. Would be interesting for someone to do a more scientific test, but there is probably a lot of variance, for example how long it takes me to take my foot off the brake and put it on the gas.
One way is to instrument the car through the OBD connector and measure the requested throttle, actual throttle, and speed from zero. I have some measurements, but need to take more. I measure through a laptop with the ktune software.
I causally tried this technique, and can see how it helps the launching. Basically there is a small delay in the release of brake, so during that 0.1-0.2s gap, the engine has rev'd up to ~2k and therefore goes to boost zone faster. Also, don't forget Funz51 is on KTuner Stage 2. This means the throttle opens (much) faster, so the brake-torque effect is more pronounced.
From my Hondata expereince, I do not feel significant brake torque in Stage 1 when using brake-hold, but Stage 2 I can feel it (even though I was not doing hard launch, but catching up with green light...)
You may ask what is the difference between manual brake-torquing and the brake-hold technique. Well, unfortunately I do not brake-torque any of my cars, so I don't know. Maybe, just maybe, the ECU does not recognize the brake-hold as applying both throttle and brake, thus allows the boost to build normally.
You may ask what is the difference between manual brake-torquing and the brake-hold technique. Well, fortunately I do not brake-torque any of my cars, so I don't know.
Fixed that for you. Dead transmission is even more annoying than delayed acceleration, IMHO.
11-29-2019, 09:10 PM
