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VSC Brake lights on - C1345 error code - will not clear - my fault?

Discussion in 'Gen 2 Prius Main Forum' started by PriusDadNoob, Jul 18, 2024 at 10:50 PM.

  1. PriusDadNoob

    PriusDadNoob Junior Member

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    2008 Prius. My steering was "loose" at speed so I connected my laptop to the OBD2 port, fired up Techstream and then... clicked the wrong buttons. Muscle memory I guess, from dealing with the brakes on several Gen 2 prius: I went into the ABS/VSC/TRAC area in techstream and did the relearn procedure instead of the going to the steering area (EMPS) and reseting the angle sensor. (resetting the angle sensor fixed my "loose" steering when I was driving over 40 MPH in the past but that is another issue)

    Now my brake light, ABS and VSC lights are all on and will not clear with Techstream or the paperclip method. (Pins 4 and 13, pump the brakes 8 times etc.) The car will drive but the brakes are not working right, they are like traditional brakes, not regenerative braking I guess.

    The thing is, the car was FINE. No lights, nothing, just that loose steering issue. This problem only occurred after I clicked the wrong button in Techstream!!! Now the error code C1345 will not go away and the brakes are not right. Did I do something wrong when I did the relearn procedure? I have searched this forum and cannot find the proper procedure for a 2008, only a PDF of the 2010 procedure.

    Here is what I tried:
    Open Techstream
    Go to Chassis
    Open ABS/VSC/TRAC
    Entered Utilities
    Ran the reset memory procedure
    Ran the Test Mode procedure
    Ran the ECB Utility - Linear Valve Offset
    Ran the Signal Check

    Errors still persist and I'm desperate as this is my daily driver!
    IMG_2364.JPG IMG_2363.JPG IMG_2362.JPG
     

    Attached Files:

    #1 PriusDadNoob, Jul 18, 2024 at 10:50 PM
  2. Tombukt2

    Tombukt2 Senior Member

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    Generally you didn't do anything wrong you just messed with something that didn't need to be messed with but that doesn't matter now so when you do the linear valve offset relearn does it do the procedure and past or fail? If it's continuously failing I fear to say you may have created something going on in the actuator circuitry.! It is possible I don't see why is this a already replaced actuator in this vehicle? If not it might be getting one so maybe it was time anyway. Hard to say especially if it's accepting the relearn procedure for the linear valve then I'm pretty stumped too maybe take the power away from the car for the night literally undo the 12 volt take the plug out of the HD battery just because or not I guess you can leave it and it's not going to make any difference Make sure the 12 volt goes dead and silent the system. And then in the morning boot everything back up and see what you got The only thing I can think of is in fact the linear valve offset is resetting and holding.
     
    #2 Tombukt2, Jul 18, 2024 at 10:58 PM
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  3. ChapmanF

    ChapmanF Senior Member

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    Do you hear it trying to learn the linear valve offset? It takes a minute or so, and makes a series of clicks and increasingly loud whooshes.

    If it isn't doing that, I wonder if there's some simple step in the repair manual prep for the procedure that has been overlooked.

    Another issue, but that is interesting; there may be a chance you fooled yourself there. Could you show a screenshot of where in the EMPS area you found an angle sensor reset?

    I am asking because, as far as I know,

    • The steering angle sensor isn't even an input to the EMPS ECU. (The steering torque sensor is, but the angle sensor is not.) The angle sensor is only an input to the skid ECU.
    • The skid ECU doesn't need you to do anything to calibrate the angle sensor. When you're driving straight ahead according to the yaw sensor and equal wheel speeds, it looks at whatever the angle sensor is reading and remembers "ok, that's zero angle."

    Or is it possible you were remembering going to the EMPS area and calibrating the torque sensor zero point?
     
    #3 ChapmanF, Jul 19, 2024 at 12:15 AM
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  4. PriusDadNoob

    PriusDadNoob Junior Member

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    Vehicle:
    2007 Prius
    Model:
    III
    @ChapmanF I checked and you are absolutely correct on the steering bit. I did the torque sensor zero point, not the angle sensor! It did seem to help with the loose steering at speed, for a few minutes, then it went back to the old feeling after restarting the car. I'm fairly certain it is providing too much power steering at speed. Perhaps I just need to replace that power steering module. I would welcome you opinion on that.

    BUT back to my major problem :-(

    It did make the series of clicks and bonks when I did the relearn. I will try to share screen shots of each screen I am using, but I am fairly certain I was on the right screen. I am not certain, however, that it was fully complete. It did say, "process complete when the light blink" (or something similar) but I did not see a final "blink" at the end of the procedure. The lights blink during the relearn, but there is not a final blink after they go solid at the last big bonk sound.

    Do you have to wait some time after the end of the procedure before exiting the test? One test says to "wait 2 seconds then wait as long as the manual says" which I do not know how long that might be. Do I need to do all the steps I described all over again each time? (Reset, Test Mode, etc.?) I have replaced the accumulator and actuator on a few of these and it's not a fun job. I'd rather not do it for a car that does not need it, and it was running fine yesterday. To answer your question I do not believe it has been replaced. Car has 253,000 miles.

    I feel certain that I can fix this via Techstream with the correct procedure. There is a chance the test literally broke the actuator (if it was about to fail??) but that seems unlikely given there were no symptoms.

    Brake fluid level is fine.
     
    #4 PriusDadNoob, Jul 19, 2024 at 7:53 AM
  5. PriusDadNoob

    PriusDadNoob Junior Member

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    @Tombukt2
    Thank you for your ideas. I will try to disconnect the 12v and HV battery overnight and see if that helps. I did the 12v battery for 45 min to no avail. What do you think could be the issue with the "actuator circuitry"? And do you know how to tell if it is actually accepting the relearn? Many YouTube videos later, people show doing the relearn and "look, the light is off!" but that is not my case :-(

    Car has 253,000 and has the original actuator as far as I know. That job is a bear and the used actuators are fairly pricey AND I am not sure that is even the problem. Would be pretty bad to do all that work and have that light still light up.

    Are there any other reset procedures or "get it out of test mode" procedures that I might be missing? It's so crazy that there were no lights on and the brakes were fine until I did that relearn accidentally!

    Any more ideas would be appreciated and thank you.
     
    #5 PriusDadNoob, Jul 19, 2024 at 8:00 AM
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