Just bought from the mother in law, she bought a new civic.

Over the past few months, the accord has taken to just shutting itself off for no reason. She was never able to give a good explanation of what happened when it shuts off, but each time it happened to her, the car needed to be boosted (Battery so dead that it would just give half a crank and give up)

Intermittent, happens whenever it wants to. Dealer can't find anything wrong (had it towed there twice)

I've been driving it around with a spare battery and a set of booster cable in the trunk, but it didn't act up in the 2-3 days I drove it.

Went on a long Sunday drive today, and it did it twice. Once while driving along at about 80 km/h, and again on the way home on the highway at 110 km/h.

It's like someone reached over and shut the key off. No sputtering, no warning, just shuts off and the doors unlock. I slide it to Neutral, and it restarted both time just fine and keeps on rolling down the highway.
There were a fair amount of potholes and spring bumps, but the two times it happened were on smoot sections...so a loose wire or something seems to be out.

I think it's one of two things....I'd assume that the doors unlocking mean that the PCM (ECM, BCM, whatever Honda calls it) saw the ignition switch being turned off, so it unlocked the doors. I'm thinking that if you stalled the engine by cutting off fuel, etc, that the doors would not unlock.
So, I'm thinking it's either the ignition switch, or the PCM.
I jiggled and wiggled the key, and smacked the bottom of the steering column around, and the ignition switch passes the smack-test.
The PCM may fail the smack-test, but I haven't gone that far yet. And if it doesn't, eeshhh....expensive stuff to just throw parts at it.

Anyone seen this before?

Thanks in advance folks!!

 

After the stall, does the car act like it does when you initially turn the key to the II position? Like the check engine light comes on for a few seconds and the relays click, etc?

If so, a flaky ignition switch seems likely. Also, check that all ends of both battery cables are clean and secure.

 

Honestly, I'm not 100% sure.

Both times it happened, it was kind of a shock, plus I had someone right behind me so I just wanted to get it started and rolling. But yeah, it would be interesting to see.
Hopefully it'll do it to me again, and I can pay closer attention.

If I remember right, I didn't turn the key back at all (stupid fear of locking the steering at 60+mph)...just slipped it into neutral, and turned it ahead to crank and it started normally.

As soon as it re-started, all the idiot lights came on and went through the usual bulb check, and so on. And the airbag light stayed on for likely 4-5 seconds after restarting. (All acted exactly the same as a normal start-up in the driveway)

Sounding like the ignition switch, isn't it...?


And because of her having to get boosted after it happened to her, I cleaned up the battery terminals, and replaced the frayed engine ground cable as soon as I got it.
I really cannot explain why she had to be boosted the times it happened to her...but she called me once, and when I got there, the battery was just about dead...just enough to turn it over very very slowly, but not enough to start it.
Each time it happened today, it whirled right over...lots of juice.
Either way, that part, I'll worry about later...battery/alternator...whichever. But the shutting down, that needs to get fixed first.

 

Ha!!! And I'm the smart-a$$ that always gives people crap for not looking for their own answers before the ask for help....

http://www.visualimpressions.ca/switch/

Looks like I found my problem.