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Automatic Engine Idle Stop Unavailable

69K views 36 replies 21 participants last post by  2020MDXLover  
#1 ·
2016 SH-AWD Advance/Entertainment

I bought this car last Thurs and every time I stop, this message pops up "Automatic Engine Idle Stop Unavailable". I made sure to press the button to enable it I even tried to drive no heat, no radio, no nav, etc but it's still not kicking in. I heard it sometimes doesn't work when it's really cold. But the other day when I drove it, it was above 40F. Any suggestion? I've scheduled to take it to the dealer next week.
 
#2 ·
They are several parameter that must be met before the idle stop activates

"Auto idle stop does not activate (or the engine may automatically restart) when the driver’s seat belt is unfastened, the vehicle is stopped on a steep hill, the windshield defroster is on, and other conditions. See the Owner’s Manual on the Owner information CD or at owners.acura.com (U.S.) or myacura.ca (Canada) for a full list of conditions."
 
#4 ·
There have been posts from other owners about the auto idle stop not working either, but they haven't been able to get resolution with Acura. I would still recommend starting the case with the dealer and escalating it through corporate. It sounds like the system is really either overactive, causing people to really hate it, or entirely inactive, which means you've basically paid for a non-functioning feature. One owner went as far as buying a Honda HDS and diagnosing himself, which lead him to a fault controller for the auto idle that he was resetting by removing/reinserting the fuse.
 
#5 ·
wow. that's a big leap in trying to troubleshoot a vehicle issue. is honda going to reimburse him for that Honda HDS kit when the techs that honda pays(?) couldnt do it themselves? or the warranty you paid for was worth the ink that was used to print out the order form?

i was thinking of buying my own Honda HDS on ebay. but was apprehensive as to the version of the firmware currently installed and whether i could update it from Honda/Acura's website?
 
#6 ·
Yeah it sucks but it's the only way to get to the bottom of things sometimes (especially since Honda/Acura loves "It's normal!"). I'm also on the fence about the ebay HDS units. They look like they will work from what I see on the forums, but nobody really knows what is the latest and greatest.
 
#7 ·
I just found out at the dealer that the Auto Idle-Stop sensor will not work if the Battery internal Temperature is below 61F (16C) degrees. I just bought a 2017 Acura MDX - Advanced+Entertainment model less than a month ago, and for the time I drove it, the AIS did not work or "Unable to Activate". They ran a diagnostic test and found out that the sensor passed all tests, EXCEPT battery temp test which it failed. The temp at time of test was around 40F for the Battery Internal Temp. Technician waited for battery to continue heat-up and found that the AIS sensor activated and worked at 61F (16C). This is in the State of Virginia. Mine was fine driving home, the engine completely stopped when I am at a stoplight, and instantaneously, restart upon releasing foot pressure on brake pedal. The info board will tell you if you are not putting enough pressure on the brake pedal during a stop. I will monitor it for a while to see if this solves the AIS issue. So far it is working for me.
 
#8 ·
I had intermittent operation of the stop/start system in my 17 Advanced. Dealer re-flashed the system and it has been working reliably for about 2 weeks now. Supposedly there's some kind of TSB about it. Dealer was told what to do by Acura help team (engineering?) And my outside temperatures have been in the 30's F, and it's been working reliably after I get the car up to normal operating temp (per the temp gauge).
 
#9 ·
Mine hasn't been working for a quite a while now. One thing I noticed that it resumed it's normal operation after I did an oil change and reset the counter. It worked fine for a few short weeks then stopped again, coincidence? Perhaps. I just don't have time to waste at the dealer on this worthless feature, IMO.
 
#10 ·
I agree about its worthlessness. It was done merely to get an extra MPG rating increase. These days manufacturers are tripping all over themselves trying to satisfy the ever-increasing CAFE standards. And that's the reason why we can turn it off with the button, but it defaults back to "on" when you restart the car next time. In order for the mileage increase to count, it cannot be defeated. My feeling was that as long as I had the feature, I wanted it to work correctly.
 
#11 ·
Update March 2017 - Been to dealer several times for this and they reflash it and it will work for a week or two then stop. It's been 8 days now without ever working. Display just says system is "unavailable". Outside temps have been between 25 and 45 degrees F. And I'm not buying that post about the battery temp having to be above 61 degrees. It has worked (when it works) in temps in the 20's, 30's, 40's, and 50's (yeah, it's been a crazy winter). Just one more thing they can't fix.
 
#16 ·
I'm not a fan of it either. It's soon gonna be hard to buy a new car without that feature, from what I'm reading in magazines. More and more models have it due to ever-tightening CAFE standards. And in my Advance, it is rated a full mpg higher because of it. And that's why you can't turn it off permanently (although if I leave it unrepaired, it's as good as permanently off <groan>). I guess if you use it to improve your mpg rating, it can't be permanently turned off. Maybe the current administration will ease the CAFE standards to more realistic levels.
 
#20 ·
Lots of good info you provided. I do believe it's the "state of charge". Once the dealer told me about the de-coupling alternator (yes, for gas mileage) it made more sense to me. They even bought me a battery maintainer and connected the quick-connect harness to the charging system so I could just pop the hood and plug in. That's fine but having to plug the car in at night... might as well buy a Tesla <grin>.
 
#21 ·
I have auto start stop. It won't work for months and then all of a sudden it works all the time (almost too much) and then it stops working for months. If your battery charge is too low (i.e you do a lot of short trips) the computer will keep your engine running at intersections to charge the battery. Take a 6 hour highway trip which will charge your battery and get your auto start stop working. Long highway trips always bring my start stop back to life again.
 
#24 ·
Hum, we just bought a 2017 MDX 2 weeks ago (2 years old, was in the showroom all that time with a dead battery when we looked at it) and this on/off auto engine worked for 3-4 days and now it won't work anymore. I didn't like the feature so it doesn't bother me but we just did a long trip (over 6 hours in 2 days) and its still off. The a/c is on in the car so maybe that's it? I wish this feature would work when its supposed to. Whats the point of having it otherwise?
 
#25 ·
I bought the 2020 AWD MDX last week. Despite turning off everything from radio to heater/AC and driving in 65 degree sunny daytime, the Automatic Engine Shut-Off fails to work. It just says its "unavailable". The dealer says its normal for it not to engage due to some mysterious undefined reason. So this added $300 to the sticker price and it does nothing?
 
#26 ·
I had the same question after I recently purchased my 2016 CPO ADV. Dealership told me that is probably because of the car sitting in the lot for few weeks and will fix itself once I start driving it regularly.
Though it took couple of days, Auto Idle Stop feature started to work.
Apparently, a number of factors determine to enable idle stop or not for safety reasons. Obviously you don't want idle stop to trigger if the battery is not fully charged, right?
 
#28 ·
I’ve had this issue on and off since I picked up my ‘17 Advance last month. After reading through all the things that make it “unavailable”, if you have eliminated those factors the last thing to try is the hood open reset I found here on the Odyssey forums:

Copy/pasta from https://www.odyclub.com/threads/auto-idle-stop-potential-fix-procedure.337977/
Procedure to try fix AIS:

  1. Take your van out for at least a 15 min trip and be sure it’s warmed up. If you have the message popup activated, confirm that is says unavailable when you come to a stop.
  2. Park somewhere safe, shutoff the van. Open the door and pop the hood.
  3. Get out and open it up and prop it up on the kickstand.
  4. Get back to the seat, start the car, close the door, confirm the message center says hood open.
  5. I got out the van, looked at engine and then went back and shut it off. I think I left the door open and leaned in to turn off, and then returned to shut the hood. (not sure if door open/close played a role yet)
  6. Get in, close the door and start normally.
  7. Take it out for a drive, and AIS should work instantly, assuming all conditions are met.
I’ve had my car to the dealer for some CPO work for other issues, and whenever I get the car back the “unavailable” thing occurs even when all the other factors are satisfied, and the steps above always seemed to fix it right away.
 
#30 ·
I’ve had this issue on and off since I picked up my ‘17 Advance last month. After reading through all the things that make it “unavailable”, if you have eliminated those factors the last thing to try is the hood open reset I found here on the Odyssey forums:

Copy/pasta from Auto Idle stop potential fix procedure


I’ve had my car to the dealer for some CPO work for other issues, and whenever I get the car back the “unavailable” thing occurs even when all the other factors are satisfied, and the steps above always seemed to fix it right away.
Do you have to do this every time you get in the car?
 
#36 ·
I had the Auto Stop Update done by Acura (TSB23-001/002) which changed the Idle Stop operating range. Since then the Auto Stop quit working. I took it back to the dealer and they said I needed a new battery (almost $400). My MDX is a 2017 and the battery was replaced in 2019. The car starts fine and when started with the lights on, they don't dim at all. The TSB does state that after the idle stop update, there may be reduced idle stop engagement when the battery is approaching the end of its useful life.
 
#37 ·
I too am experiencing this issue. I got a gem of. 2020 with the technology package with only 13,000 miles!! Everything works but the auto stop. The car has been sitting in the dealer lot, tons of on/offs and playing with the accessories. Last night alone I was tweaking my android auto with just the accessory on. My guess is mines not working because of "lower" voltage. I tested the resting voltage and I'm at about 12.5-12.6. I put it on a battery maintainer and we'll see if the auto stop comes on after the battery has fully come up to charge.

Funny enough, when we got the car home I told my wife to always turn it off when she's driving as I'd rather not have the wear and tear on the starter. But it's a feature that should work so I'll keep and eye on it and take it to the dealer if it continues.

Here's the beauty I picked up. My first ever Acura as well!!
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