Output Control Warning Light - the 'turtle' coming on intermittently

Discussion in 'Generation 1 Prius Discussion' started by Debora, Jul 9, 2014.

  1. Debora

    Debora Junior Member

    Jul 18, 2007
    Greetings PriusChat forum members,

    First of all, I have to say I love Prius Chat. It has always been my first reference point when troubleshooting and you have saved me thousands of dollars!

    I have a 2002 Prius that looks like new and is still going strong. I was driving down the mountain from Lake Cachuma to Santa Barbara a 20-minute decline of probably 1,000 feet. Anyway, I put it in 'B' drive on the way down (my mistake, I thought that the B drive was used to help charge the electric battery which now I know is incorrect). The Output Control Warning Light came on and acceleration was goofy. Then the light went off and stayed off for 2 days, the whole drive back from Santa Barbara to Los Angeles. Then yesterday, I drove through the mountains on a hot 95 degree day, everything was fine but when I got back in the car to return home an hour later, the light came on when I started up the engine and it stayed on for about 20 minutes and the acceleration was really scary, eg I stepped on the acceleration pedal and nothing happened until I floored the pedal.
    Any ideas on what this is??? I am thinking my wonderful car is overheating and I need to replace the electric battery filter vents which has never been done.

    Thanks, Debora
  2. Easy Rider

    Easy Rider Active Member

    Feb 9, 2014
    N. Central Florida
    2013 Prius c
    It certainly would be good to check the battery vents and filters but beyond that, this problem might require professional help to diagnose.
    There may be stored codes that would help with finding the problem.

    The car IS 12 years old now. How many miles ??
  3. ChapmanF

    ChapmanF Senior Member

    Mar 30, 2008
    Indiana, USA
    2010 Prius
    A long sustained descent, or mountain driving on a very hot day, are both conditions that might legitimately bring on your turtle light. I got mine for a few minutes last summer while driving down to the bottom of New River Gorge and back up (rather slow and winding). Sure, it won't hurt to check whether the vents are clean, fan works, etc., but other than that, don't worry too much - the car is doing what it's supposed to for protecting itself.

    Your use of B on the long descent was not a mistake - the car will do some regen in either D or B, but B will also allow some energy to be 'burned off' by spinning the engine to dissipate it, to put less stress on the battery during a long descent. What you did was good.

    By now, you've gained some experience of what the acceleration will be like when output-control is active, so if you get the turtle light again sometime you'll be familiar and know what to expect. Basically, when you see that light, the trick is to drive very mindfully of avoiding situations where you'll need more power than you can get.