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ABS, Brake, and Skid light on with Buzzer

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Al Sanchez, May 7, 2022.

  1. Al Sanchez

    Al Sanchez New Member

    Joined:
    May 7, 2022
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    Location:
    California
    Vehicle:
    2011 Prius
    Model:
    Two
    Driving home march 29, 2022 and all of the sudden I heard a little noise and noticed that the regenerative braking was no longer working and the ABS, VSC and Brake light turned on. Drove it to AutoZone and got the code C1391, indicating an issue with the accumulator pressure. Also, the accumulator was turning on in 2-second intervals and constantly replaced the accumulator; reinstalled the original actuator.

    After replacing the accumulator, we reconnected the hybrid battery and the 12 volt battery, turned the key on, vehicle had a constant and loud beeping was immediately present and it had a message about checking the hybrid system and the big triangle with and exclamation point.

    The same warning lights were on the dash for the brakes and ABS. This was concerning as the beeping and the message were not present before we replaced the accumulator. We unplugged the actuator wiring harness and the beeping would stop AND VEHCILE WOULD NOT DRIVE, START OR PUT INTO GEAR.

    Tried manually and with a jumper pin to bleed the brakes and clear any codes, nothing changed.

    We ordered the Techstream software as we knew we would have to bleed the brakes, perform the linear valve calibration and would have to do the zero-point calibration after reading more of the manual and chat group messages.
    Replaced actuator, nothing changed. See codes below.
    upload_2022-5-6_22-31-47.png

    Took it to a local shop and they tested with their SNAP on Tester. Unable to put into any testing mode.
    We warrantied actuator assembly.
    Replaced brake Actuator assembly, bled the brakes, reset the memory, tried to perform linear reset. None of the functions would reset. Vehicle would start and run however beeping and brake system clearly not working properly.
    Codes still present as of today 5/6/22 are 1256 and 1345
    checked Fuses, grounds and wiring from accumulator at actuator connector and all are good. Pins 1, 2, 12, 14 and 15 all have power.
    Grounds: 23 24 25 26 27 are good.
    Accumulator pump is running and connector A18 for signal to Brake computer pin 29 is good also.

    Brake lamp circuit pin 33 and pin 6 are receiving power as well.

    We are at our wits end on this one, any help or direction would be appreciated.



    After replacing the brake actuator, we cleared and checked codes, currently were: C1203, C 1256, C1345, C1451,
     
    #1 Al Sanchez, May 7, 2022
  2. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
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    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    I don't see if this is Jen two or three my Gen 2 I replaced an accumulator pump assembly and could never get the card ready again but I think the way you describe the part this is a gen 3 I don't look forward to doing this in my gen 3 either but I know it's coming and there is a parts problem
     
    #2 Tombukt2, May 7, 2022
  3. Mr. F

    Mr. F Active Member

    Joined:
    Sep 21, 2020
    346
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    Location:
    Washington
    Vehicle:
    2010 Prius
    Model:
    IV
    Was a charger connected to the 12V battery while bleeding the brakes? A drained battery can sometimes result in a C1256—if so it might be prudent to connect a charger and complete the remaining steps. If a charger had not been connected, I would actually redo the bleeding with the charger on to ensure it completed successfully. This step would also take care of the linear solenoid valve offset learning, but if those values got reset (resulting in a C1345), you would need to perform it separately.

    Perform the initialization and calibration of the linear solenoid valve with the parking brake released. Referring to pages 942-943 of the repair manual:
    2. PERFORM INITIALIZATION AND CALIBRATION OF LINEAR SOLENOID VALVE (When Using the Techstream)
    (a) Clear the stored linear solenoid valve calibration data.
    (b) Perform initialization and calibration of the linear solenoid valve.​
    Only (b) from page 943 is necessary.

    Next, perform yaw rate and acceleration sensor zero point calibration. Referring to pages 947-948 of the repair manual:
    2. OBTAIN ZERO POINT OF YAW RATE AND ACCELERATION SENSOR (When Using the Techstream)
    (a) Clear the zero point calibration data.
    (b) Perform the zero point calibration of the yaw rate and acceleration sensor.​
    Make sure to only perform (b) from page 948—if you perform (a) first, you will need to redo the initialization and calibration of the linear solenoid valve and zero point calibration of the yaw rate and acceleration sensor.
     

    Attached Files:

    #3 Mr. F, May 10, 2022
    Last edited: May 10, 2022
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