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Murphy’s Law with my OBD2 reader
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tom66:
5W bulb (~450mA) @ 16 hours parked = 7.2Ah

A normal car battery should hold 50~120Ah so, unless the battery is totally knackered or was at a very low state of charge, it's probably not that.

Though it is possible that keeping that light on prevents some of the CAN bus from going to sleep, and that could then pull 50-100W.  Depends on whether the bulb is just running via a switch and a connection to "+12V_always" or if it goes back to the body module to do things like dim the bulb after it turns off or light it up when the vehicle is unlocked. 

Modern cars just seem to exude complexity for such trivial reasons.
sokoloff:

--- Quote from: edy on January 02, 2023, 05:52:04 pm ---I am going to assume at this point that it was a temporary glitch and that it won’t happen again. Seems like it is likely a sensor or wiring issue but hopefully unlikely to actually be a mechanical flaw underlying what this sensor is actually looking for. Maybe just something when doing a cold start on a day after a weekend not driving, took a few more cranks to get going, and not so much oil (before I added some more)… If the timing belt, crank shaft position or actual mechanical issue still there it would have retained the MIL and probably caused some noticeable engine problems yet I am driving fine and light went off on it’s own. Any thoughts?
--- End quote ---
P0341 on Hondas can be caused by low oil pressure, which can be caused by low oil level (but usually only by a quite low oil level, like more than 1 quart low/lower than the low mark on the dipstick). There is a variable valve timing mechanism that is actuated via oil pressure and, if the ECU commands the timing to change and doesn't see the change reflected in the sensor, will set this code.

Adding oil was a good corrective action.
Monitoring the oil level somewhat more frequently in a car known to use/leak it is probably indicated.
gnuarm:

--- Quote from: edy on January 04, 2023, 01:36:08 pm ---So after charging up the battery last night and starting the car, this morning I woke up to a dead battery. I charged it up again just enough to start the car and then noticed the light at the back (for the hatchback trunk on a CR-V) was set to permanently “on”!!!  |O So that’s probably what drained the battery overnight. I don’t know how long it has been that way. Anyways I managed to drive to work and brought all my charging gear. I didn’t disconnect the battery so we will see if there is still a drain somewhere or if I found the culprit.

--- End quote ---

I expect an LED bulb replacement would make the battery survive more than just overnight. 

I've always found those switches to be other than intuitive.  They typically are three position switches and there's no inherent logic to which position is which.  Add in that many dome lights now have a delayed off and you can't even test the switch to see which position is which... not easily anyway.
edy:
I have a feeling the trunk hatchback light was on for more than 1 night. As I mentioned before the sluggish cranking started at least a week ago and likely preceded the engine MIL code as it was doing it then too (which is why I thought maybe that triggered a false code). In any case, when I charged up the battery last night it was just enough to start the engine. The charger indicated “75%” charge but I don’t think it is a linear scale. Charger only has 5 lights. The first light is “connected”, as soon as it detects a battery it will then show the “25%” light and it has “50%”, “75%” and a final green “complete” light. So I bet it was a partial charge hence why it didn’t make it through the night even with that single light on.

I was able to crank the engine and start it last night and then immediately turned off the car. It was then sitting again all night with that hatchback light on. Yes it’s a 3 position switch (always off, related to door opening/closing, and always on). When in the middle, it will turn on when you unlock or lock doors and usually will dim off when you start engine and drive or when you lock car after a minute will dim off. However it’s hard to notice it, especially if you lock car with remote and walk away.

Anyways this morning since I couldn’t start the car I charged up my battery again for about 45 minutes. First 20 minutes brought it up to “50%”. Tried to crank car, didn’t start and battery fissled out. Then I charged battery more for another 25-30 minutes and it still only made it to “50%”… however it started the car this time. All that time I still didn’t notice the hatchback light on until finally after the car started!  |O Drove to work (30 min away), parked whole day and started car no problem for the drive home. So I suspect that light was the culprit, and because the battery was only partially charged all this time it was enough to deplete it enough not to allow it to turn over the engine. Just to be sure I’m going to charge up the battery in my car for an extended period of time when I’m home and see if it ever gets to “complete”. I’ll keep an eye on things but I believe the battery still has life left in it, once I get it up to normal full charge.
gnuarm:
If a 45 minute charge didn't let the car start, I'm thinking the battery is near done.  I've always been told a battery needs a 24 hour charge to really be "topped off properly", so charge it a couple of nights.  I don't know how far your work is, but driving is not a great way to charge the battery. 

I hope this fixes your problem.
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