4 Dashboard light always on

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Emanuele Viani, Sep 30, 2022.

  1. Emanuele Viani

    Emanuele Viani New Member

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    Hello dear friends
    My toyota prius apparently works well
    but I have always this 4 light ON

    The lights are:
    Parking brake (even though it's off!)
    (!)
    ABS
    VSC

    I had thi errors WhatsApp Image 2022-09-30 at 18.02.03.jpeg
    U011
    P0AE0

    After having deleted them, however, the lights do not go out

    It would appear to be an electrical or battery problem
    As I repeat the machine apparently works well

    As I said, deleting the error queue does not shut down
    the warning lights

    Removal of the service battery and the traction battery
    they do not turn off these lights

    What exactly is wrong with my car?
    And what am I risking? Since the machine is working at the moment
    correctly ?
     
  2. ChapmanF

    ChapmanF Senior Member

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    A scan tool was used that did not show you all of the trouble codes. We have a thread here that reviews a variety of code scanning apps and indicates which ones can read all of the codes from your Prius.

    Gen2 OBD2 app review | PriusChat

    Sort of by definition, "the machine is working at the moment correctly" is false if there are warning lights. If the system's self-diagnostics are able to alert you to problems before you would notice the problems yourself, that's what makes them useful. Sometimes a problem will be easier or less expensive to solve when it is caught early, before you actually notice that the machine will not get you where you are going.

    As a convenience when you do not have a good scan tool at hand, the warning lights you mention are able to indicate the trouble codes by blinking patterns that you can count, if you apply a jumper wire between the Tc and CG terminals of the car's diagnostic port. A search of these forums can find many threads with more detail on doing that.

    That method will also not show all possible trouble codes in the car—a good scan tool is needed for that—but the codes it reports will be a start.
     
  3. Tombukt2

    Tombukt2 Senior Member

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    My 2 Gen2 had this 3xact scenario and twas my brake actuator both times. 09 and 05 cars 05 in 2021. The 09 2022. The events happened 09 fixed . 05 not needed traction battery and host of other things parts car now almost stripped.
     
  4. dolj

    dolj Senior Member

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    The thing is, that light combination could be more than a hundred possible faults, including ABS issues, so for you to have an ABS issue is not surprising. However, for it to be that fault every time is not a given.

    As ChapmanF says in post #2, getting all the codes is the surest way to get to the root of the problem.
     
  5. Emanuele Viani

    Emanuele Viani New Member

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    I did as you suggested
    and I found the following codes
    (!) 41 65
    ABS 42
    VSC 45
     
  6. ChapmanF

    ChapmanF Senior Member

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    ABS 42 and VSC 45 both simply mean "hey, ((!)) has codes, have you looked there?".

    ECB 41 is trouble code C1241, which pertains to weird supply voltage reaching the skid control ECU. That's not always because of a 12 volt battery problem; it can be anything in the wiring bringing the power to the ECU. But if the battery voltage hasn't been checked yet, a C1241 code makes a good excuse to check it. You should be able to find more about that code by searching for it.

    ECB 65 is trouble code C1344, a complaint about controlling the hydraulic pressure to the rear left brake. There are about 8 pages for troubleshooting that in the repair manual.

    There's at least some possibility that straightening out the supply voltage issue might resolve the C1344. Worth a try, anyway.
     
  7. Emanuele Viani

    Emanuele Viani New Member

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    Battery is 14.0V is good ?

    For now the car brakes correctly
    even if regenerative braking has stopped.

    I have read in other forums that if the brake situation becomes
    dangerous, a buzzer should sound.

    Can you confirm that?
     

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  8. bisco

    bisco cookie crumbler

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    14v is the inverter power. measure with car off
     
  9. ChapmanF

    ChapmanF Senior Member

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    There is a buzzer that sounds when certain trouble codes are logged, and indicates particularly dangerous situations.

    Those aren't the only risky situations though. The system is already telling you about a problem with power reaching the brake ECU, and a problem controlling hydraulic pressure to one of the brakes.
     
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