Error codes after replacing brake actuator

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Trumanator, Sep 7, 2021.

  1. Trumanator

    Trumanator New Member

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    I have a 2010 Prius with 161k miles on it and the brake actuator went bad. I just missed the cutoff for Toyota's coverage, so I hired a hybrid mechanic to replace the parts for me. I bought a brand new actuator and pump assembly from Toyota and the mechanic did the work. The mechanic replaced the bad actuator and bled the brakes manually. Now I have three new error codes C1203, C1345, C1451. The mechanic tried the paperclip trick, but that did not clear the codes. The mechanic thinks that I need to take it to the dealer to "reprogram the actuator". Does this sound right?
     
  2. JC91006

    JC91006 Senior Member

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    Where did you find this "hybrid mechanic"? The brakes are bled using a computer/scanner tool, not manually.
     
  3. ChapmanF

    ChapmanF Senior Member

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    The C1451 is a rather stubborn code that the brake ECU sets to make sure that a brake bleed gets done. Nothing clears C1451. Not disconnecting the battery, not a clear command from a scan tool, not any code-clearing chicken dance. The only thing that makes C1451 go away is to connect Techstream and follow its brake bleeding sequence through to completion. The code locks out the brake pump motor until that is done.

    C1345 is easy; there is a "linear solenoid offset learning" procedure that needs to be gone through, and it can be started with a couple clicks in Techstream and it just sits there making pumpy-squirty noises for a minute or two and it's done, easy peasy. But it requires the pump motor not being locked out, so deal with the C1451 first.

    I get a little nervous any time I see a thread with C1203. That code is not very deeply explained in the repair manual, and what is there suggests that this code is set when the new actuator compares calibration details with other modules like the ECM, power management control ECU, and yaw/accel sensor, and decides it doesn't really belong in this car. That might be what the mechanic is looking at and thinking about how to "reprogram" it, but if the dealer had any actual details on how to do that, the repair manual is where I would expect to find them, and I don't.

    I have definitely seen threads where people had a C1203 and then eventually got it to go away, after sometimes large amounts of faffing around that don't make it easy to say "ok, do X, that's what worked." If the brake ECU is actually not communicating with other modules, sometimes fixing that might be enough.

    So that's the code that tends to give me the biggest vicarious headache, just because I simply don't have enough information to give you steps that I'm sure will fix it.
     
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  4. Trumanator

    Trumanator New Member

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    I found him on google. He has good reviews and seems knowledgeable for the most part. He is also way cheaper than the dealer. That being said, I'm starting to question my decision of using him.
     
  5. Trumanator

    Trumanator New Member

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    Thank you for your detailed response! I have an appointment with Toyota this week. It sounds like they should be able to take care of C1451 and C1345 fairly easily. I've seen some videos on Youtube where taking care of the first two codes clears C1203, so I'm hopeful that will be the case. When my mechanic originally saw the code, he thought that he might have to replace the control harness. However, he suggested taking it to Toyota to see what they say at this point.
     
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