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2004 Prius VSC, ABS, (!) and emergency brake light on

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by robl45, Dec 5, 2016.

  1. robl45

    robl45 Member

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    Hello,

    When driving to work today, the VSC, ABS, (!) and emergency brake light came on and stayed on. I read through here quickly and did the diagnostic test on the screen and the battery appears to be okay. dropped to about 11.8 under load, charging is 14.0-14.2. I checked the fluid reservoir and I took off the cap and see bubbles while it is running. Car still seems to be braking okay. The brake relay thing does run every few seconds that I can hear under the front dash. The car seems to brake fine and I really don't use the brakes much, really just braking from the electric motor. Is there anything else to check?
     
  2. bisco

    bisco cookie crumbler

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    the best thing would be to have the codes read, or buy a mini vci for diy? also better to check the battery directly with a volt meter.
     
  3. robl45

    robl45 Member

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    I don't have a code reader but I will try the paper clip thing to get the codes if I can manage to find how to do it again. If anyone can post here how to do it so I can find it easily later, that would be great.
     
  4. JC91006

    JC91006 Senior Member

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    There's probably a problem with your hv battery. You should get the codes read.

    The 12v battery at 11.8v is low, but shouldn't be the problem here
     
  5. robl45

    robl45 Member

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    ! I got 5-7. Abs. 4-2. Vsc. 4-5
     
  6. bisco

    bisco cookie crumbler

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    what is that?
     
  7. robl45

    robl45 Member

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    The blink codes from jumpering the obd port.
     
  8. bisco

    bisco cookie crumbler

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    oh, i see. i don't know how to decipher those, have you tried google?
     
  9. robl45

    robl45 Member

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    Yes, I googled, did not really find anything on the codes. I checked twice to make sure I wrote them correctly.
     
  10. bisco

    bisco cookie crumbler

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    the regular codes come up on google. maybe you can subscribe to toyoatechinfo for the descriptions, or look through the technical forum.
     
  11. robl45

    robl45 Member

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    So I reset it with the paperclip trick and it was fine, until I just slightly tapped the emergency brake. I was driving and decided to make sure I could hit it in case the brakes really have a problem. I barely touched it and the lights came back on. I cleared the lights again when I got home. This started after I upped the tire pressure yesterday from around 30psi that they were on to 35psi. I made no other changes and have been driving this 100 miles a day during the week for a over a month already. Could this cause it?
     
  12. bisco

    bisco cookie crumbler

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    not that i know of, could your e brake be sticking?
     
  13. robl45

    robl45 Member

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    I don't think so, I hit the ebrake when I got home and then released it. Could increasing the pressure cause this? Only thing I changed.
     
  14. bisco

    bisco cookie crumbler

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    i increase my pressure all the time, never had any lights come on. maybe jack her up and see if all the wheels spin freely, or go for a long ride and see if one feels hotter than the others.
     
  15. robl45

    robl45 Member

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    Could this really be an issue since I drive 100 miles a day and my gas mileage is 49mpg? I'd assume I'd notice a drastic decrease.
     
  16. GT4Prius

    GT4Prius Active Member

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    I had exactly these warning lights. It happened intermittently for a while.

    It turned out to be traction battery EDIT (terminal not technical) terminal corrosion due to rain leaking into the car from a faulty hatchback door seal.

    Posted via the PriusChat mobile app.
     
    #16 GT4Prius, Dec 6, 2016
    Last edited: Dec 6, 2016
  17. robl45

    robl45 Member

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    Lights came back After 40miles. Anyone have any ideas on the codes?
     
  18. GT4Prius

    GT4Prius Active Member

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    Did you see my suggestion?

    After corrosion was repaired car has been fine now for two years.

    Posted via the PriusChat mobile app.
     
  19. dolj

    dolj Senior Member

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    I don't know how accurate these are, but here's what I found.

    ELECTRONICALLY CONTROLLED BRAKE SYSTEM

    NOTICE:

    When replacing the brake booster with master cylinder (skid control ECU), sensor, etc., make sure that the power switch is turned off, the stop light switch is off, and 2 minutes have elapsed since the driver's door was closed.

    HINT:
    •  If no abnormality is found when inspecting parts, inspect the skid control ECU and ground points for poor connections.
    •  When 2 or more DTCs are detected, perform circuit inspections one by one until the problem is identified.
    •  Inspect the fuses and relays before inspecting the trouble areas as shown in the table below.

    ABS 42 Electronically Controlled Brake System Malfunction
    • Electronically controlled brake system
    VSC 45 Electronically Controlled Brake System Malfunction
    • Electronically controlled brake system
    57 (C1257) Power Supply Drive Circuit. Inf Codes 361, 362. Brake booster with master cylinder (Skid control ECU)
     
  20. robl45

    robl45 Member

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    Thank you very much, could someone translate this into english for me. I'm not sure exactly what I would be looking at. Is this something I can troubleshoot myself?