Red triangle of death, c1310, c1256 after reconmecting battery

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Knudson, Mar 8, 2024.

  1. Knudson

    Knudson New Member

    Joined:
    Mar 8, 2024
    2
    0
    0
    Location:
    Austin TX
    Vehicle:
    2006 Prius
    Model:
    N/A
    Two days ago, I left my 2006 Prius in ready mode overnight and ran down the month old 12v battery so low that it couldn’t be jumped. I ended up having to remove the batttery and used a trickle charger overnight (there were no outlets nearby where the car was parked so had to remove it to charge it). After reconnecting the battery, the car ran great, I was getting even better gas mileage, etc. Then today I got the red triangle and used an OBDII to scan it. I got c1310 and c1256 codes., but the car seems to be driving fine. Any ideas?
     
  2. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    11,692
    2,072
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Check your battery voltage again and make sure you are at 12 volts or better car sitting not on and 135 or above with the car ready. You know what to see 1310 and the other code are check Make sure those problems are covered clear the codes and see what happens.
     
  3. Knudson

    Knudson New Member

    Joined:
    Mar 8, 2024
    2
    0
    0
    Location:
    Austin TX
    Vehicle:
    2006 Prius
    Model:
    N/A
    Thank you, will try that!
     
  4. Brian1954

    Brian1954 Senior Member

    Joined:
    Jan 31, 2021
    1,626
    627
    0
    Location:
    South Central PA, USA
    Vehicle:
    2011 Prius
    Model:
    III
    Your statement does not make any sense to me. If the car was left in ready mode, the 12v battery would be charged by the hybrid vehicle (HV) battery and would not "run down". The HV battery would "run down" until the point where the ICE would start and charge the HV battery. As long as you do not run out of gas, the HV and 12v batteries would remain charged.

    If the car was left in accessory mode, then 12v battery would run down.

    What scanner are you using to read the trouble codes? I am guessing that you also have HV battery codes, but your scanner is not capable of reading them.