Hi all, Got a strange issue with my 2010 prius. I press on brake and power on but while my dash turns on, my after market stereo and the engine do not start. I release brake and press power button to power off. Press on brake to start back up and it'll start up normally. Sometimes I might need to repeat. I did notice tonight that if I had lights on before starting, it wouldn't start up at all until I turned off lights. I did have one start up where 30 seconds after I powered it on, the stereo display lit up then I could start the engine without powering off first. This started happening about a month ago after I went on vacation for about 9 days. When it is started properly, I don't see any check engine lights. I checked the 12V battery and it was around 12.4V. My best guess now is my aftermarket stereo was sipping power causing some issue. The aftermarket stereo is one of those chinese Android Auto/CarPlay devices.
The problem is probably the 12v battery. How old is the battery? How much do you drive the car during the week?
Where did you check the battery? At the battery terminals or the jump point, under the hood? You may have loose or dirty terminal connections.
12.4 volts is low for a Prius. How old is the battery? If it's 6 or more years, it's likely time for a new one. You could try charging it for 6-8 hours at 5 amps or less.
sometimes people hit the power button too fast before the brake switch is fully depressed, going into acc mode
The battery was replaced recently in the last year or so. I measured it at the terminals of the battery. I can try to charge it once I find something to charge it with. I drive the car maybe 4 to 5 hours a week top since my commute is short.
That doesn't matter; You could have a parasitic drain on your battery and/or vampire after market electronics NOT shutting off. People have found tracking units installed in their cars, by dealerships that began to malfunction and drained the battery.
This is likely why it is weak. You're not driving enough. How long after replacing the radio did this start happening? You can get a AGM 5 amp charger at walfart, or auto parts store. You could also get trickle charger, or maintainer. Charging it once a month over night will likely resolve your issue, it that is the problem.
This is the 1st time that I've experienced this since changing out the stereo. It probably drained over the trip. The stereo has a setting where it fully turns off after a set time but I guess that was still too long. I already got the charger and am letting it charge overnight. Started at about half charge according to the bars on the charger.
You should be good after charging. It's normal for it to have a drain. The 12v battery is not a high amperage one because it doesn't need to start the engine. And the inverter charges slowly. You could wire in a cord to the battery so you can easily plug in the charger once a month or so....
Late update but after getting battery to 12.9V it seems to be fine. Will need to look into setting stereo to turn off sooner or manually turn it off before long trips next time. Thanks yall.
