acuratester

Bought a 2019 Acura RDX a couple of weeks back, so far so good.Not sure if it has been like that from the start or its happening recently, but I am observing that engine is struggling in the initial low gears every time I press the accelerator after coming to a complete stop at traffic signals or stop signs. There is no problem with the pick up, but engine roars with loud sound struggling a little bit in the starting and then it takes off.
Just wanted to check if anyone has observed this or may be it is happening only to my vehicle

Dereileak

sounds like the same behavior as mine and all the RDXs, if your at a dead stop and floor it power is great and you take off, if your coming to a stop but havnt completely stop and then step on it there is a delay in power for a good second maybe even 1.5-2 seconds before you get power, probably related to the turbo spooling and the tranny adjusting gears, sounds normal for the 19 RDX

cm2021

That happens if I need heavy acceleration from a stop or at low speeds. I place the transmission in S to avoid this when I know I need more power.

patriotsfan82

This is pretty much my RDX as well. If you are slowing down for whatever reason, not quite stopped, and decide to get going, the transmission gets so confused. I would prefer it stick in the wrong gear for a moment and recover once it starts responding. Outside of my CarPlay issues, its the most annoying thing on my RDX.

Slack Machine

Yeah, I usually downshift a gear or two to get quick response. This issue almost caused a collision early on when I couldn’t get out of the way of an oncoming car as I was turning at a light. Not fun.

Steve2019

I have had a similar problem the past two weeks. When I stop for light then accelerate the car goes slow and the engine is reving. I have had to pull off-road and turn car off before being able to drive. I have also tried to put car intocruise control and it hasn’t worked. I have had the RDX since June of 2018 and I have over 26000 miles.

Stew4HD

Take it to the dealer ASAP

NooYawkuh

Look for the thread on "limp mode". That's what that sounds like. Although most don't experience it just from normal acceleration from a standing start. That's not normal.

Any transmission can get "confused" and gear-hunt depending on the speed of the vehicle and the RPM of the engine, even a 5 or 6 speed. Maybe more so in the RDX, which is a 10-speed (like a Schwinn ). The only oddity I notice sometimes is the tranny stays in a lower gear longer than I think it should while I'm accelerating. Almost as if I'm in Sport/S mode even though I'm in Comfort/D. But the car does accelerate. It doesn't slug out, so I don't think there's a problem.

Alias1431

Some people will tell you that it's turbo-lag at low RPM. While totally valid, and partially true, I'm thinking the issue has more to do with poor transmission programming. Anyone else think this?

JB in AZ

Making the assumption this lag we are discussing is when the Idle/stop is disabled....let me add some of my thoughts to your thinking, it might be partially transmission programming. However, at a stop, if one doesn't have a foot on the brake, the car will creep forward, so I assume that it is in 1st gear at this point, so where is the problem with the programming? Not sure. Perhaps it is poor throttle programming? I think I have read others report the lag is either much less or non-existent if S mode (from D/S button) or Sport or Sport + is used,

If we are talking about an almost stop, then reapply throttle, it may be a combination throttle/transmission programming.

Just thinking.

Wander

Incomplete stop/deceleration, followed by sudden request for acceleration............ ANY TIME NOW!

Typical example is turning across traffic from a slow roll, after waiting for a gap.

Punching the D/S button to "S" or dialing the Big Shiny Knob up to "Sport+" can help mitigate the effect. But ya gotta do it in advance.

I don't think it's just turbo lag.

Stew4HD

Agreed, it's the transmission searching for the proper gear

JB in AZ

But, isn't the transmission already in first gear at this point? What is it searching for?

Stew4HD

I believe is does not into shift to first until you are completely stopped. If I do even a hesitation stop, many times the transmission searches/hesitates.

corners

I noticed this when I was test driving the RDX last month. This is another reason why I have not pulled the trigger on buying the RDX. I seen this happening in Audi Q5 as well.

NooYawkuh

Let me understand exactly what we're talking about here. We're not talking about accelerating from a standing start. Correct? We're talking about slowing down but before you come to a stop, you accelerate. The torque converter is usually unlocked when the transmission is downshifting, especially in the lower gears at low RPM. It may not transfer torque right away if you suddenly accelerate. It may seem like it's slipping because you're in the hysteresis region of any two gears.

I'm sure I've experienced this with almost any AT car I've ever owned. Even older ones that were almost entirely based on hydraulic pressures with little or no electronic control.

corners

For some this is a deal breaker. Including me! So what are the chances of this getting fixed in the 2020 model? Will this type of performance be a normal thing?

NooYawkuh

I don't know. I don't work for Acura and I don't know if there's actually a problem. I haven't experienced it in the six weeks I've owned the car, so I don't know how prevalent it is, if at all. But I'll bet if I really try, I could make the car do it. I'd bet I could make your car do it, whatever it is, if it has an automatic transmission.

I have heard about people describing "gear hunting" in reviews on a lot of new cars, including the RDX. Supposedly the 9-speed in the Gen 3 Honda Pilot was very prone to it but they've improved it for 2019. I personally experienced it in my test drive of the Lexus RX. But that wasn't the only reason I didn't buy the car.

I can say that the more I drive the RDX, the better sense and feel I get of how the car responds to the throttle and the better performance I'm getting. I don't even think about it. It's intuitive.

grandicornis

If you have the Dynamic mode set to Snow that would start you in 2nd and make it kind of slugish too.

Wander

An "unlocked" torque converter is perfectly capable of transferring torque, and even multiplying it, but only if torque is being provided to it. The "locking" mechanism ( clutch ) improves efficiency under cruising conditions, it does not improve acceleration. If anything, failure of the TC to unlock may hinder low-rpm acceleration, although that's less of an issue with 10 ratios to work with than it was with 3.

More relevant is the state of the A/T clutches. And IMO most relevant is the state of the computerized drivetrain controllers, which clearly get flustered under some conditions.

During the event described, which I can readily reproduce ( sadly ), I don't get the sense that the drivetrain is slipping; it's just not responding. The lack of response usually leads to an additional thrust of the right pedal, which probably results in some more computational and/or mechanical uncertainty, and then the thing revs up near redline and surges forward, as my passenger's eyes bug out of her head as she stares at the rapidly approaching oncoming vehicle.

Wander

BTW, said passenger usually glares at me after one of these events and says "You know, if you put the thing in Sport+ mode, it won't do that!".

Maybe that's why I married her?

Steve2019

Thanks, I had it in sports mode and changed it to comfort which I prefer anyway.

thetrev68

It feels to me more like it's ignoring the pedal press. I push it and nothing happens, then I panic and push it further, then it lurches forward. For me, I only seem to notice it when I'm turning as well - not in straight line acceleration. It's worse in Comfort mode but happens in Sport as well. I haven't noticed it happen in Sport+ or if I use the "S" over the "D" on the transmission. It can be very scary if you are pulling out in front of oncoming traffic.

I have an oil change coming up soon, and I plan to have them evaluate the fly-by-wire accelerator system for a possible issue.

RDX-Rick

I experience the same symptom on my 2016 Elite(i.e. delay in acceleration when turning).

I have determined that it is the collision avoidance system. The problem only happens when there is another vehicle a few feet in front of me. When I turn the wheel, and step on the accelerator to begin my turn, the CMBS doesn't know that the wheel is turned, and it disables the accelerator to prevent me from running into the car in front of me.

In the early days I would continue pushing the accelerator to the floor in order to turn left in front of oncoming traffic. Since then I have learned that the car won't move any faster no matter how far I push the pedal. I can reduce the symptom somewhat by making sure the car in front of me is a little further ahead, and then letting the nose of the car turn at an angle to the left before pressing the accelerator. I assume this works because the car in front is no longer detected by the radar or cameras.

BTW, we have an intersection in our city where the roads meet at an angle. If I need to stop in the intersection while the car in front makes a turn, I also experience the delay in accelerating because the CMBS sees a telephone pole directly in front of me.

NOTE: The "BRAKE" message does not appear on the MID during these situations. I think trying to accelerate when an object is in front of you is a special case for CMBS.

Wander

Gonna have them debug the code?

I agree completely with your description of the behavior, but the "fly-by-wire accelerator" isn't just an electrically controlled "throttle", the whole darn engine/transmission package is controlled by multiple computers supposedly working together to make the right things happen at the right times. Let's be glad this isn't a Boeing jet.

The shop can check for "trouble codes" the system may have generated if it detects a problem, but aside from that there's not much they can do. I'm afraid this is an issue for engineering. And it will probably take a while before there's a resolution.

As for the collision mitigation system, I'm not sure what to think about that. It seems unlikely that's involved since there is no warning generated. But it does make me think about other systems, like traction control and stability control. There's a lot of moving parts here.

As for possible changes for 2020, it's possible there have already been changes to more recent production of 2019 RDX vehicles. That's not something Acura is going to talk about unless and until they release a fix for earlier production vehicles.

Alias1431

This.
It's like it can't understand gradual throttle application in 1st gear. So you apply more throttle until the computer or whatever sees that it crosses some magical threshold, and then all of a sudden it's like OH SHIT HE WANTS TO GO, and it slams you back in your seat.
I'm convinced this is not 100% turbo lag. I know in my heart that this is something that can be resolved, or at least improved, with better throttle and/or transmission programming.

RDX-Rick

Well the theory is easy enough to prove or disprove. We need someone who is experiencing the problem, attempt to accelerate from a low speed on a STRAIGHT road and NO VEHICLES in front.

This feature is widely advertised on Subaru's with EyeSight. Although I could not find anything with Google that confirms Honda/Acura has a similar feature, I experience it frequently in my 2016 RDX.

Have a look at this Subaru video and see how the feature would cause the symptoms being described in this thread, I have never seen any indication on the dash when I experience this operating.

https://www.youtube.com/watch?v=qPNO...=youtu.be&t=26

samiam_68

I'm so glad my 15 doesn't have any of these nanny systems.

NooYawkuh

All of them can be turned off. Or, you can leave them on and, on most, you can adjust their sensitivity / threshold. My previous cars didn't have any of these features and I thought I would turn them off but I left them all on at the default settings and they don't bother me. The only one I Ieave off is the parking sensor. It goes increasingly nuts when pull into the garage. I can always turn it on if I need it by pressing the button.