Carbon monoxide alert

J

jorgie393

Well-Known Member
So, finally made a consequential error. I’ve had a Clarity since 2019, love it. Park it in an enclosed attached garage with charger.

Newish driver age 18 uses the car, parked in the garage. Must have powered it off, then started it up again in accessory mode (I’ve done this a few times by hitting the power twice when I think it didn’t turn off the first time). Not 100% sure. Didn’t plug it into charger.

As best I can tell, overnight therefore it ran the heater and other accessories until the battery was used up, then started up the engine to recharge the battery.

Noticed a funny, faint, smell in the morning, more near the garage, opened the interior house-to-garage door and was baffled to find the garage quite hot (engine was off at that moment so it was confusing). A few seconds later, the carbon monoxide detectors in the house 20 ft away started to go off, more than 800 ppm (which is a dangerous level). Open the main garage door, got in and took the car out of accessory mode (a mistake, should’ve just gotten out of there, but did note the battery level was zero), left, then put it all together.

No harm done, carboxyhemoglobin (a measure of CO poisoning) in the emergency department was only about six or 7%, which is barely more than smokers, but could’ve been consequential. If for example, I had close the garage door behind me and spent more time poking around in the garage for what was going on with the main door closed.

Moral of the story: teach new drivers to double check that the car is truly off if it beeps when you close the door. Also to always plug in the charger if it’s inside (though I’m not 100% sure it will charge in accessory mode or other).

Likely to put a carbon monoxide detector in the garage itself, which, of course would be ridiculous for an ICE car, but here might work, unless it triggers on those occasions when I have to drive home on pure engine.

[Edit: actually, it appears the car was left in a mode that has no name – it’s what you get if you hit power on twice without your foot on the brake. First press is accessory mode, in which heat, etc. don’t run. Second press, display states “ to start car, put foot on the brake” . Driving is not possible, but In this mode, heat and everything can draw power and therefore drain the battery. I can’t tell if having a charger in or not makes a difference or if this nameless mode is so close to driving that it rejects charging.].
 
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Wow...
Thanks for reporting this. I would not have anticipated such a scenario.

For me, this is even more important because we have gotten accustomed to driving a Tesla.
With a Tesla, you just exit (you never explicitly turn it off) and there have been a few occasions where we exited the Clarity and [almost] forgot to turn it off. After your experience, it is tempting to install a CO detector in our garage too.
 
Scary stuff!

Cars should not start themselves (IMO) without some driver input/push notification/or something. I would report this to Honda.

Also, what were you smelling? just the regular exhaust? CO is odorless, so whatever you were smelling wasn't the CO, probably just the exhaust itself.

I usually keep my garage windows cracked even through winter so there is fresh air to come in, at least a little bit.
 
So far, we don’t know exactly what happened, do we? Quite likely the car was left on (READY) in HV mode. In that scenario, the traction battery gets depleted a bit, then the engine runs to restore the charge, before shutting off until the battery is drained a little bit again. It could also have been left on (READY) in EV mode, in which case the engine would come on when EV range = 0 or 2 bars are displayed on the gauge. Then it’s the same rinse and repeat cycle as in HV mode.

Perhaps someone could confirm, but I don’t believe the engine will run when the car is in Accessory or ON mode. Regardless, in all likelihood, the car functioned normally as designed. What this boils down to is someone operating a vehicle who doesn’t understand how to operate the vehicle. The car doesn’t know if it’s in a garage or on the road, so the operator needs to put the vehicle in a safe mode when it’s parked in a garage.

Calling Honda to report this would only serve to make the caller look foolish. Take responsibility for what happened.
 
I think i'll just add to this discussion that climate control on Clarity doesn't start the gas engine from the "off" position in my experience.
If you schedule or remote start climate and SOC goes low, Climate will turn off, but will not start the engine. I've been using scheduled and remote climate settings frequently including disconnected, level 1, and level 2 connected. In ~7 years, climate control itself has never engaged the gas engine for me. So less of a concern for remote/scheduled climate.

Feature request wise, I think it would of been nice if Clarity made a lot more of a fuss when one walks away with the FOB and the car is still on. Maybe this is the case where you go full obnoxious and sound the horn like some car-security systems do. As it is, I do think it beeps at you, but I can imagine someone missing the beep if they walk away too quickly.

My own pattern, and I do think this has helped me, is that I always plugin the J1772 charge cord when in the garage. The car displays an error if you try to charge and the vehicle is still on. Something with a red X or similar. Text says something like you need to turn off the car to charge. Anyway, this combination has resulted in a useful reminder to turn off the car. (Rarely, I have initially forgotten, but I get this mesage, and I presume I'd get a beep too if I walked away). Maybe its just a discipline that must be mastered, or put the charge cord in the driveway to avoid garage altogether. Anyway, hope this helps a future reader.
 
Landshark said:
So far, we don’t know exactly what happened, do we? Quite likely the car was left on (READY) in HV mode. In that scenario, the traction battery gets depleted a bit, then the engine runs to restore the charge, before shutting off until the battery is drained a little bit again. It could also have been left on (READY) in EV mode, in which case the engine would come on when EV range = 0 or 2 bars are displayed on the gauge. Then it’s the same rinse and repeat cycle as in HV mode.

Perhaps someone could confirm, but I don’t believe the engine will run when the car is in Accessory or ON mode. Regardless, in all likelihood, the car functioned normally as designed. What this boils down to is someone operating a vehicle who doesn’t understand how to operate the vehicle. The car doesn’t know if it’s in a garage or on the road, so the operator needs to put the vehicle in a safe mode when it’s parked in a garage.

Calling Honda to report this would only serve to make the caller look foolish. Take responsibility for what happened.
Click to expand...
Yep. But as I added, in an edit tonal post, it was neither on, nor in accessory mode. I didn’t add why I knew this, but:

When I walked up to the car, I could see clearly that the display was fully on (before getting in) and it said “to start car, press brake, and hit power “, or words that effect. So I agree, it was not an accessory mode. It was also not on. It’s in that strange mode which you get if you hit the power button on twice with your foot off the brake. And in that mode, it seems to have the worst combination of: running the accessories to drop power, and able to turn the engine on to recharge the battery.
 
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