[MrCar]

The battery drain on these cars is rather intense (everything is electronic). If you have a 2+ year-old battery and the weather is cold, that could be an issue.

 

[stevelit]

Anyone had their engine failed to start after idle stop engaged? I have had this happen 3 or more times over last 2 weeks. Essentially, engine tries to start but fails, causing me to have to put the car in Park and hit start button. Rather frustrating as this takes time and causes cars behind you start honking.

I have a 2015. After about 3 years, it started happening to me. I had the battery and starting system checked and no problems were found. Yet it kept happening erratically. I finally decided to change the battery and no more problems. I got one at my local tire store ($180). It has 730 CCA which is more than the OEM battery. Make sure it's a glass-mat battery. Good luck.

 

[chtnwmw]

I have a 2016 Pilot Touring which has the same 3.5L engine and 9-sp ZF transmission. The battery lasted about 2.5 years before it started stalling on traffic light. The battery is replaced under factory warranty and I have since disabled Idle stop permanently.

 

[stevelit]

I have a 2015 and mine started failing to restart after the car was about 2 years old. It would almost always fail to start when I came off the highway and hit a red light at the exit ramp. After failing to restart, I would turn the car off, it would always restart. When it did that with my wife in the car, she had a heart attack and from then on with her in the car I always turned it off before taking her anywhere. Like everyone above, I took it to the dealer to check the battery, starter, computer, and everything else and it always came back with no issues found. After not using it for a year or so, I tried it again and it failed to restart, after exiting the highway and at red lights after driving for a while. Even though the car always started in the morning through the winter, I decided it could be a weak battery and decided to replace it, since the car was 4 years old at that point. I put in an Interstate MTX 48/H6 760CCA battery in and haven't had a problem since. The OEM battery is only 640CCA so this should be better. It cost me $225 which was $100 cheaper than the OEM Acura battery from the dealer. My recommendation to everyone - get rid of the weak OEM battery and put in a good one!

 

[MrMoo]

I think a big issue is the charging strategy these cars have. Cars used to constantly charge the battery. Now they try to only charge the battery during low loads, such as coasting to a stop. They do this to improve fuel economy.

 

[TrickVert]

Different vehicle, but our 2016 Jeep will disable the auto-engine-stop feature if/when the battery starts to fail. I noticed it wasn't working, but had no other indications that the battery was starting to go south until attempting to start the vehicle more than twice in a row, after which it would either slow crank and start or fail to do so. A new Interstate battery last year, and all has been well.

 

[Goawayidlestop]

I’ve seen at least a handful of these at my dealership and we have not been able to figure out the exact cause of the problem. The engineers have been out from Honda looking at it and still have come to know conclusion. We replaced batteries, starters, alternators, battery cables and battery sensors all with no luck. When the car fails to restart it saves a data list snapshot and on all of these cars the battery voltage drops to around 6V at the time it fails to restart which causes the car not to restart even though it passed the original test to auto idle stop in the first place. It seems likely that it may be a software issue within the PCM battery voltage sensing circuit because all parts we have replaced have not Corrected the issue. There’s really not much parts left to replace in the electrical battery sensing system really the PCM is the only thing left which points to software

 

[Sue Beck]

Anyone had their engine failed to start after idle stop engaged? I have had this happen 3 or more times over last 2 weeks. Essentially, engine tries to start but fails, causing me to have to put the car in Park and hit start button. Rather frustrating as this takes time and causes cars behind you start honking.

This happened several times - leaving me stranded in traffic. Finally, the battery tested bad and acura replaced it. Now, I try to disable it every time I start the car. Had company in the car the other day - and missed disabling it. To my dismay - when I went to start up at a stop light the car failed to restart. I put it in park - and it still took a number of times hitting the start button before it started up again. Good grief. There needs to be a fix for this issue.

 

[Goawayidlestop]

There needs to be a fix for this issue.

I would think the issue would have to be solved at some point as it can create dangerous situations when it leaves you stuck at intersections. Honda is going to have to do something....It just plain isn’t safe to be stuck at a stoplight in any amount of traffic. For now, until Honda figures out the issue, you just have to disable the idle stop system or remember to make turning it off as part of your startup routine.

 

[Andrew Reedman]

In my view, the faulty start/stop design is a safety issue. This is a problem I've had with both my 2015 and 2017 TLX (V6 SH-AWD Tech). I've been to three dealers and each of them stared blankly at me and said "well we test drove it and it's working fine now". When I reported that my 2017 was experiencing a significant delay between gears when shifting from drive to reverse, they said "that's just the way the car is". Everything in this car is electronically controlled, so I'm reasonably certain that all of this is the result of Acura's incredibly glitchy software. Acura's refusal to deal with this (and other problems) means that I will deal with it - by switching to a Genesis G70 when my lease is up in a month. Au revoir Acura.

 

[illmatic905]

Hi all, just sharing something that I think worked for me.... I bought a battery charger to recharge my battery, and now it seems to be fixed. In particular I bought the Noco Genius 2 (from Amazon). Keeping my battery charged or at maintenance seems to have made things normal again.

What I went through:
I had the same issue recently where my 2015 TLX V6 AWD stopped at a light from auto idle. I took it to my dealer and they mentioned that they would need to charge me $150 to diagnose the car. The service rep mentiond that battery issues or replacing a battery isn't covered by the warranty. Rather than doing that I was pretty sure my battery was weak and wondered if a charge would help...it did!

The rep mentioned that the TLX's system should know when the battery is low, and not engage the auto idle shutoff in that case. I'm sure this is glitchy (for everyone) and isn't working properly.

As I expected, leaving the car sitting on my garage for weeks in the winter cold weakened my battery. Either driving or keeping it charged is important for the auto idle shutoff to work. I haven't been driving much because of the recent Covid lockdown.

I hope this helps someone else out there. DM me if there's anything I can help with.

 

[ngking1]

I replaced my battery with a non AGM battery and it didn't fix the issue. Infact it made it worse. I'm going to replace the battery again with an AGM and see how it goes. I have a 2018 acura TLX A-Spec with 100 clicks. Will update the thread after a few small drives

 

[Sue Beck]

Anyone had their engine failed to start after idle stop engaged? I have had this happen 3 or more times over last 2 weeks. Essentially, engine tries to start but fails, causing me to have to put the car in Park and hit start button. Rather frustrating as this takes time and causes cars behind you start honking.

Yes mine has done this as well. It’s a 2018 TLX. The battery has been replaced at the Acura dealership and it has still reoccurred so now whenever I take the brake off I push the button to disengage auto engine stop