I spent several weeks out of town on business recently, so I haven't driven my RDX much since the end of August. On the dozen or so drives I took last week, the auto idle stop didn't kick in one time. I've confirmed that I can disarm and re-arm it with the dash button, and that I see the corresponding message on the display. At first I just dismissed it as some ambient temp/humidity veto that I didn't know about, but the longer it persists the less convinced I am.

Then yesterday I engaged lane keep assist during the freeway section of my morning commute (I normally don't bother because it's only 15 km or so), and noticed that it never prompted me for steering input. From the time I engaged LKA until I reached my exit I never touched the wheel and never received the prompt. LKA worked flawlessly aside from the absence of the prompt after 15 seconds of no steering input.

Both of these systems worked as advertised for the first month, before I parked it and went abroad for several weeks. Now I'm wondering if these are two symptoms of the same problem. One of the auto idle stop vetoes is steering input, which makes me think maybe there's a problem with the steering input sensor registering a false positive.

 

Things are getting colder up here and i've also noticed the auto idle stop hasn't worked in a while. There is a long list of qualifiers which will negate its operation....one of which is use of the climate control system and front defrost. I've needed both quite a lot the past few weeks.

 

It probably also checks your battery voltage and won't engage if your battery state of charge is a little low which might be the case if the car has sat idle.

 

Haven't yet seen a recurrence of the indefinite LKA, but the auto idle stop still hasn't activated one single time since August.

 

since my car has been new the 15 second lka warning has been sometimes 1 minute, sometimes several minutes, sometimes never, but im fine with that, as long as it doesn't warn me after im touching the wheel. As far as the auto start stop there are some specific things that will cause it not to enable, I notice it doesn't do it was much when its been cold, but my engine hasn't been up to temp for some of my driving when it did that, since its about 15 degrees f here

 

 

From what I've read there are a lot of "parameters" that will over-ride the stop/start feature. On hot days with the AC running it may not shut off the engine otherwise the AC would run off battery (not good).....or heavy stop and go traffic or creeping a few feet at a time in traffic.....and possibly in cold weather when the heater fan, heated seats and/or defroster are on.

Perhaps that's what you are experiencing........and (to me) another reason why I think it's a terrible system that "saves so little fuel" its a joke. AND....no matter what they say, causes unnecessary wear on the battery and starter, etc.

 

 

 

...probably because when the car senses "cold outside temps" it ASSUMES you might be running the heater blower motor ...so to prevent the power for that blower to come from the battery (if the engine had shut down) they have designed it to keep the engine running and power the blower.....as I wrote, there are lots of designed perimeters that over-ride the auto start stop feature.

 

http://techinfo.honda.com/rjanisis/p...BTJB1919OM.PDF

page 430

Auto Idle Stop does not activate when:
• The Auto Idle Stop OFF button is pressed.
• The driver’s seat belt is not fastened.
• The engine coolant temperature is low or high.
• The transmission fluid temperature is low or high.
• The vehicle comes to a stop again before the vehicle speed reaches 3 mph (5
km/h) after the engine starts.
• Stopped on a steep incline.
• The transmission is in a position other than (D.
• The engine is started with the hood open.
u Turn off the engine. Close the hood before you restart the engine to activate
Auto Idle Stop.
• The battery charge is low.
• The internal temperature of the battery is 14°F (−10°C). or less.
• The climate control system is in use, and the outside temperature is below −4°F
(−20°C) or over 104°F (40°C).
• The climate control system is in use, and the temperature is set to the Hi or Lo.
• is ON (indicator on).
• The dynamic mode is changed to Snow or Sport+ mode.
■ Auto Idle Stop Activates When: 1Auto Idle Stop Activates When:
When ACC with LSF is in operation, the vehicle stops
without depressing the brake pedal and Auto Idle
Stop may activate.
Do not open the hood while the Auto Idle Stop
function is activated. If the hood is opened, the
engine will not restart automatically.
In this case, restart the engine with the ENGINE
START/STOP button.
2 Starting the Engine P. 411
Pressing the ENGINE START/STOP button changes
the power mode to OFF even while Auto Idle Stop is
in operation. Once in OFF, the engine no longer
restarts automatically. Follow the standard procedure
to start the engine.
2 Starting the Engine P. 411
19 ACURA RDX-31TJB6000.book 430 ページ ２０１８年４月２６日　木曜日　午後４時５１分
431
uuWhen DrivinguAuto Idle Stop
Continued
Driving
■ Auto Idle Stop may not activate when:
• The vehicle is stopped by braking suddenly.
• The steering wheel is operated.
• Altitude is high.
• The vehicle is repeatedly accelerated and decelerated at a low speed.
• The climate control system is in use, and there is a significant difference between
the set temperature and the actual interior temperature.
• The climate control system is in use, and humidity in the interior is high.

 

 

Mine won't stay on longer than 2 minutes or so, not even through a traffic light cycle. I'm getting ready to just turn it off and be done with it.

 

 

 

I wouldn't be too worried about the battery health. With the auto stop system a lot of the TLX owners have found that when the battery starts to get weak the system will actually let the auto stop shut off the engine, but then not automatically start the car once the brake pedal is released. They have to cycle the push button start a few times to get the car to start when this happens.

You will probably find that the dealer will test the battery (which will probably test fine), and then do a computer reset to the system which will reboot the auto stop system and you will be back to having to press the auto stop cancel button every time you start the car. If it were me, I would count my blessings for now until the system resets on its own and you are back to hitting the cancel button again. If you are worried about your battery, I am sure your local Acura dealer would test the battery for you with their hand held tester, which should only take about 10 minutes, if that.

 

I may be in the minority here, but while I find the restart just a bit more "noticeable" than ideal, and don't find it overly objectionable, I prefer to use the idle stop. Granted I have only owned the RDX for a month. Averaging ~28 mpg in mostly suburban driving isn't bad.

 

 

 

Why would I do that? I consider my currently non-functional idle auto-stop a major upgrade to the vehicle!

 

While I don't mind it (yet), I read on a Pilot forum that they figured out a way to permanently disable the function...Disclosure: I'm not an electrical engineer. I'm guessing it is similar to the RDX.

disable idle stop

 

I just got a 2019 MDX and have not been able to get the auto stop working. Even in 75+ degree weather with the AC off. My Mercedes C300 didnt have all of these conditions for it to start working. The C300 would be able to auto stop 30 seconds after leaving my house. Honda's system really sucks.

 

On the RDX if you have the temperature set to LO, it will not engage idle auto stop. I set mine to 58 degrees when not using heat or AC, and idle stop works as expected. I can't speak for the MDX.

 

Probably too many short trips to the grocery store that runs down your battery. Take a longer trip to charge up and it'll work as it should. Honda system works great when you understand your vehicle and read the manual.

 

My 2019 MDX it works much better now that the temperature warmed up. I live in MN and in winter while it would shut off the engine, it would turn back on again after only a few mins unless I turn off the climate control system, which I assume is due to the radical difference in temp between outside (-10F) and inside the vehicle (75F). Now that temp outside is 40-70F when the engine shuts off it stays off until I release the gas pedal even if climate control is on. If yours isn't working and isn't disabled then I'd take it to the dealer and have them look at it.

 

On my 2019 RDX, AIS never worked from initial purchase last summer. I took it in once soon after I bought the car but the service advisor talked me out of even getting it checked, explaining that one of the many overrides must be getting in the way. I let it go until the first service a few weeks ago. They kept it a couple of days as the first attempts to fix it including reset were not successful. They finally found the problem was the "secondary hood latch sensor" which apparently is the mechanism to ensure AIS doesn't engage with the hood open.

I considered not saying anything based on some of the feedback I read here. But, now that I have it, I'm fine with it and am enjoying a boost in MPG, at least as calculated by the car. I've learned that just lifting my foot off the brake a little will restart the car whenever I want, such as just before I believe a light is going green.

 

Same here. I've also learned to slightly depress the brake enough to not trigger the AIS if I know I'll be proceeding shortly after. Considering that AIS is in almost every modern car now, I have accepted it and hasn't bothered me at all.

 

And, as I have mentioned, during the time of year when it is possible, setting the inside temperature to LO in manual mode...will keep it from engaging as well.. But I don't mind it either.

 

After not working for three months, mine suddenly started working again after another 7-hour drive.
Weird.

 

Same here....May is warmer than Feb.

 

Mine magically started working today too, lo these many months after I started this thread.

 

Must be a secret over-the-air update😏

 

I went on vacation and left it parked for 10 days, and now it's stopped stopping again.

 

Of course it stopped working after parked for 10 days. It’s all about the charge level of your battery. If you use your RDX as mainly a grocery hauler with short trips, your battery may never reach the level to activate auto/stop.

 

Objection, your honour! Counsel is assuming facts not in evidence.

This sort of condescending BS is why I'm checking out of this forum. Goodbye all.

 

Wow! Perhaps you are overreacting, just a bit? RobinL offered a reason for your experience.
There are many reasons the auto stop will not function.

Without getting on your wrong side, have you read the section on this in the manual?

 

opening and closing the hood with engine running will disable your auto stop feature. when disable it will not reset, there is a procedure to do so:
1 Get car to operating temperature - confirm that the system says unavailable when stopped
2 Park somewhere safe, open the drivers door and pop the hood, open the hood completely up
3 With the hood opened, get back into the car, close the door and start the engine, confirm that the dash displays hood opened message
4, Shut off the engine, open the drivers door and go shut the hood.
5. The system is active now, it should work instantly

You just successfully reset the AIS system.

There is a way to disable it permanently as well using the open hood trick, but I let someone else figure that puzzle out. Mine AIS was not working at all from the dealer, because the smart look over the car technician did not know how to properly inspect the car, he was sharp enough to put ugly dealership sticker on the back of my car though, so he is paid for something, I took sticker away, but scratched the paint ever so slightly with my nail... oh well,

Good luck with the procedure and if your AIS dose not work, the steps outlined above are sure to reset it for you...

 

Mine has stopped working the past few days, but it didn't just stop "stopping". I actually get a message on the center dash display that says "Auto Engine Stop Unavailable".

I've gotten this message since Saturday when I did the map update.

 

Probably battery charge state. I bet after a few longer drives the battery will be back to a full state and the message will disappear.

 

This happens when the engine is too cold, or the battery hasn't saved up enough juice yet. Not a broken system.