1. Attachments are working again! Check out this thread for more details and to report any other bugs.

My 2009 Prius had problems starting!

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by rubberpill2002, Feb 8, 2009.

  1. rubberpill2002

    rubberpill2002 New Member

    Joined:
    Jan 21, 2009
    10
    0
    0
    Location:
    Wilmington, DE
    Vehicle:
    2009 Prius
    We just bought a brand new 2009 Prius 8 days ago and have put only 500 miles on the car. We went out to the car today and the keyless entry would not work and and the car would not ulock, so I used the key to gain entry and when I got in the car it would not start. The check engine light flashed every time I pushed the power button. We left the car there and came back in an an hour and it started and drove fine. Any ideas of what might be going on? This does not inspire a lot of confidence in Toyota, the car is a WEEK OLD!!!
     
  2. richard schumacher

    richard schumacher shortbus driver

    Joined:
    Mar 27, 2004
    7,663
    1,038
    0
    Location:
    United States
    Vehicle:
    2004 Prius
    Model:
    N/A
    Simplest explanation: somebody drained the 12V battery. The possibilities get less likely and more expensive from there. Make certain that all lights are off and the car is locked every time you park it, at home also.
     
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,199
    6,464
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    If you agree with Richard that the 12V battery may have been drained inadvertently (or maybe it was not sufficiently charged before you took delivery) then leave the car READY for several hours to give the battery a chance to charge up. It is not necessary to actually drive the car during this period (unless you want to.)
     
  4. rubberpill2002

    rubberpill2002 New Member

    Joined:
    Jan 21, 2009
    10
    0
    0
    Location:
    Wilmington, DE
    Vehicle:
    2009 Prius
    Does the hybrid battery recharge the 12v? Is this why the car was able to start later? Thanks!
     
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,199
    6,464
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Any recharging happens only when the car is READY. Perhaps ambient temps warmed up later in the day so the 12V battery may have had a bit more power then.

    Here is a brief overview of how the batteries interact:

    The traction battery provides high voltage (nominal rating 201.6VDC) to the DC/DC converter when the car is READY. The output of the converter is a regulated 13.8VDC. Since the 12V battery is attached to the 12V bus, it will charge up when the car is READY as 13.8V is available at that time.

    The traction battery state-of-charge is continually monitored by an ECU dedicated to this task and located within the traction battery enclosure. When the traction battery needs to be recharged, the gasoline engine will turn on and spin MG1. AC voltage from MG1 goes through the inverter and becomes DC (voltage around 220-230V or so) which charges the traction battery.