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Gen 2 ABS Actuator VIN Locked?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by BigBlackBunny, Jul 15, 2021.

  1. BigBlackBunny

    BigBlackBunny Junior Member

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    I have been googling for an hour, and just cant seem to find other posts talking about this.

    I dropped by 08 Prius Touring off to the dealer today for a brake diagnosis. There is no pressure to the back brakes at all. Warning lights were BRAKE, ((!)), and ABS. They called back an hour later, saying that the brake actuator needed to be replaced. Quoted me $3,200.

    I asked if I can just pop in a $30 gen 2 Prius ABS actuator I got from the U Pull, and they said it would never work as the ABS units are VIN locked. VIN locked? Is that true? I thought I had seen threads around here of ABS replacements, where nothing about a VIN lock was ever mentioned. I cant find a reference to Gen 2 Prius ABS VIN lock anywhere on multiple search engines. Are they full of it, or am I really not going to be able to replace this actuator with a used part?

    I do have TechStream on a laptop with a broken screen. Perfectly happy to fix it up and pay for anything to do it myself, as I'm trying to get into repairing Gen 2 Prii anyways. I have a small fleet of them, and I have a lot to learn.
     
  2. PriusCamper

    PriusCamper Senior Member

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    They're full of it...
     
  3. TMR-JWAP

    TMR-JWAP Senior Member

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    They are totally full of baloney. The only thing to keep in mind is each ABS module is paired with a matching resistor, 90% of DIY swaps don't do the resistor because it was never removed from the donor car. Not really a big deal, just may make the pump a bit noisier than factory.

    Don't forget you'll need to do a good brake bleed and probably a few techstream procedures.
     
  4. BigBlackBunny

    BigBlackBunny Junior Member

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    Thank you, I knew my BS meter was going off for a reason.

    Where is that resistor located? I pulled an ABS out of a Gen 2 prius at the U Pull. Perhaps I should go grab the resistor before it leaves the yard?

    I just ordered a new (old) Windows XP laptop from Ebay. My old TechStream was in a virtual machine on a tablet, but it gave me a lot of problems. Time to set it up right.

    I figure I need to do the brake bleed and possibly do an ABS ECU reprogramming through TechStream. Any other procedures?

    When I picked up the car today, they tried to not include the TechStream printout. The tech saw me an immediately went around the corner for an early lunch break...at 10:08 AM. The manager gave a weird look when another employee mentioned the early break. I had the manager print out the TechStream for me.

    Looks like for ABS related codes, I did at least get:
    C1343 - problem achieving the target brake pressure in the right-rear brake line
    C1344 - problem achieving the target brake pressure in the left-rear brake line

    It shows the previous owner had brought the car to a shop before. These codes did not show up on my TechStream report. They got:
    C1256 - Accumulator Low Pressure
    C1253 - Brake Booster Pump Motor Circuit

    Would this show that previously, the ABS was getting weak, and now the two rear wheel solenoids have ceased functioning? At that point, they did have the C1343, but not the C1344.
     
  5. PriusCamper

    PriusCamper Senior Member

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    Are you sure there's zero functioning in the rear, or just low pressure?
     
  6. BigBlackBunny

    BigBlackBunny Junior Member

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    I had put the rear wheels on jack stands, hand spun the wheels, and pressed the brake. This didn't even slow the tires down a little.

    I tried purging any air from the brake lines after that. While I did get an extremely weak brake fluid flow and a little air, it didn't flow nearly as fast as what would be expected when bleeding brakes. I got the same amount of fluid out in about 3 minutes, as I would expect within seconds with a typical brake bleed.
     
  7. ChapmanF

    ChapmanF Senior Member

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    Was the system in invalid mode? If it is trying to control, and it believes there's a weird pressure drop in a line, it may valve off that line to conserve fluid.
     
  8. Another

    Another Senior Member

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    see brake actuator resistor | PriusChat
     
  9. BigBlackBunny

    BigBlackBunny Junior Member

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    I did have the key in the house while I tried to do the brake bleed. Is that the proper way for invalid mode in a Gen 2? Is the procedure to get it in invalid mode, the same as a gen 3? I found Invalid mode vs. Battery disconnect, but that post seems to be about a Gen 3 prius.

    Thanks, I'll look for that resistor.
     
  10. ChapmanF

    ChapmanF Senior Member

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    Given the location where they buried it, it may not be worth the trouble, unless you'd be really put out by the pump being a smidgen louder.
     
  11. BigBlackBunny

    BigBlackBunny Junior Member

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    I'm not terribly put off my the pump being a bit louder, but I do want to dig through every part of these cars, as I intend to learn everything about them. Both for personal use reasons, and for flipping them. Every time a Prius hits one of my local U-Pull yards, I've been stripping them down and just leaving most of the parts there, only taking parts I need for one of my Prii and to sell some on Ebay. These brake actuators sell like hot cakes, so I just happened to already have one on hand that I'm not listing for in case I end up needing it for this repair.

    Is there a part that leads to both rear brake lines that may be damaged? As both rear brakes are showing this issue, perhaps its some proportioning valve? Or perhaps one rear brake going, forced the other one to go as well?