‘18 TLX A-Spec - 36000km on it

Been some cold mornings on NB Canada lately. always relied on the auto start to keep my ass warm.
Lately it’s been failing. Dealer can’t get me in for a few weeks.
Remote indicates failed start attempt.
I go outside to try again.
It offers a weak attempt to turn over, a strange piston sounds, like a short hiss, and won’t start.
Does this intermittently. More in cold days.

This is paired with intermittent idle stop restart issues.

I’ve suggested likely battery faults but service guy blew off idea.

I’ll be bringing it in and not accepting close minded service to blow me off in person, but any insight or experience to assist with further suggestions?

 

It's the battery. Acura will do a load test. It's a specific process with a specific tester - the details of which can be found in a doc somewhere on this forum if you dig hard enough - that takes about 1.5 hours. Owners have had varying degrees of success getting it to fail. Many dealers including mine said it passed. In that case, you can choose to buy a $300+ battery from Acura, or go buy your own for ~$200.

AutoZone also does free tests. They showed my battery at 60% capacity after a 45 min drive on the expressway. I recommend Duralast Platinum AGM.

 

I'm in Quebec,Canada and I've had similar issues, and many more. I'm currently sewing Honda for multiple issues [ie: Engine vibrations issue, Safety issues such as Engine stalls (after an Auto Stop-Start) and transmission shifts to 'N', etc.] I also happen to be one "lucky" owner of a blue painted TLX, which also has a paint issue (but not exclusively around the rear window as stipulated in the technical service bulletin) on multiple parts.

That being said, in April 2018, Acura(Honda) had my battery changed under warranty, as well as a tiny sensor (located on the battery) which communicates to other TLX systems what's the level of charge of the battery. Despite this, I still have the same engine stalls issues. Some experts I've hired are wondering if this could not be linked to the fuel pump recall that has been issued in USA but not in Canada. I'm not a mechanics, but I'm wondering if the hissing noise you are describing may be just that.
So far, for my TLX, 6 new engine injectors, new shocks absorbers, new engine and transmission mounts, new transmission, new paint (rear window), etc. have not solve any problem... I wish you good luck.

 

This problem has happened to many members already and is going to get worse as the vehicle and battery ages. The auto idle stop will prematurely wear your battery and cause most agm batteries to fail after only 3-4 years. The agm batteries are expensive as hell! I hade the Idlestopper installed on my TLX to turn off the idle stop system and save myself from ya omg to spend $$$$ on new batteries.
I would guess the battery is your problem as well for your remote start issue. Here is the Idlestopper link to their website. http://www.idlestopper.com