[jppelec]

Yesterday morning when I started my 2021 Passport The information screen had A message that the security system was not connected and to press and hold the power button for two seconds to reconnect. After doing what it instructed the screen came back. Now my passport doesn’t get driven much and sits sometimes a couple of weeks in the garage so I suspected The battery might be getting weak, I tested it and sure enough it only had 12.1 volts. I connected it overnight to my Battery Minder that is rated for AGM batteries and this morning it was at 13.5 volts where it belongs. Anyone else have this happen with a weak battery?

 

[fx_chip]

I never experienced this but I think you diagnosed the problem pretty well. Your car battery charge must have dropped below a set threshold when the ignition system took a power draw from it, that gave the security system the impression that the vehicle's battery was disconnected and that triggered the Audio System Theft Protection System.

 

[jppelec]

I never experienced this but I think you diagnosed the problem pretty well. Your car battery charge must have dropped below a set threshold when the ignition system took a power draw from it, that gave the security system the impression that the vehicle's battery was disconnected and that triggered the Audio System Theft Protection System.

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Yes I think you are correct. I have read a lot about these AGM batteries and they have a higher resting voltage then a normal battery. I was pleasantly surprised that the BatteryMinder I purchased a few years ago was compatible with a AGM battery. Presently it is in desulfurization mode and the battery is back to 100%. I have to bring It in for a inspection and oil change in November and will have them check the battery as it’s still under warranty.

 

[PLwalto]

Yesterday morning when I started my 2021 Passport The information screen had A message that the security system was not connected and to press and hold the power button for two seconds to reconnect. After doing what it instructed the screen came back. Now my passport doesn’t get driven much and sits sometimes a couple of weeks in the garage so I suspected The battery might be getting weak, I tested it and sure enough it only had 12.1 volts. I connected it overnight to my Battery Minder that is rated for AGM batteries and this morning it was at 13.5 volts where it belongs. Anyone else have this happen with a weak battery?

Be careful with this. I have a 2019 passport that started doing this but that was the least of my problems. After that weird electronic stuff would happen but the worst of all is the auto idle does not behave and the car will just randomly shut off. Turns out the latter is a known problem that Honda isn’t talking about but the NHTSA does and has filed a complaint against Honda. However to this point they are saying nothing to their dealerships. The issue affects both PPs and pilots. My dealership seems to think the problem is related to the voltage regulator in the 9 speed V6s. But again there is no solution except I have to make sure I turn the auto idle off every time I run the car. Good luck, but it sounds like it’s your battery. And in my case a new battery will have the car running well for about 8 months and the problem starts again.