Brake Light ABS & VSC lights on with OBD codes C1241and C1343

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Look2C, May 6, 2021.

  1. Look2C

    Look2C New Member

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    I have a 2008 Prius with over 250K miles. Today several warning lights came on (Brake light, ! light, ABS and VSC) on starting the vehicle. I called the dealer to make sure it was safe to drive over 1 hr to the service department. He said that it could be the hydraulic brake master cylinder going out. He checked my year as there had been a warranty extension but found it had expired in 2018. He said it could be the Brake Actuator and I could be looking at $3200 (noting that they had to do diagnostics to be sure).

    I got 2 codes (C1241 and C1343) with the OBD2. Before spending $$$ I thought I'd explore Prius Chat as it helped me successfully replace the combination meter 15 months ago. I'm not a mechanic or adept at complex repairs but I'm good at following very detailed instructions. It's just that I don't want to delve too deeply if this is a repair beyond my capability.

    Any help is greatly appreciated!
     
  2. ChapmanF

    ChapmanF Senior Member

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    Neither one of those codes is a slam dunk for a failing actuator (and certainly not for the master cylinder, which in Gen 2 is a separate part).

    The C1241 refers to an out-of-spec voltage being measured at the brake ECU, which could be as simple as a wiring or connector problem (or even just a really low charge on the 12 volt battery). The C1343 refers to difficulty holding the pressure constant in the right rear brake line, and could be connected to simple things like leaks or rotor warpage.

    If you're good at following very detailed instructions, my suggestion would be to go straight to the repair manual (more info), look up the workup sections for those two codes, and do that.

    It is possible that following the workup steps will lead you to the brake actuator ultimately, but it's not the only possibility, so that's how you'll find out.

    For that C1343 there should be a three-digit "INF code" that will give you an extra head start on the workup.
     
  3. Look2C

    Look2C New Member

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    Thank you for steering me towards the available repair manuals. I was able to pull up the DTC Codes from the Power Library for free under their E- resources. They even list the INF codes. Unfortunately our Zurich 13 OBD2 doesn't provide subcodes and nor does Autozone.

    So we're left to explore what we can see and understand. Voltage on the battery checked out fine at 12.47V.

    Tomorrow we will inspect wire harnesses and fuses. Plan to jack up the rear wheel to explore the brakes closer but we don't have the scan software to do an air bleed. Ultimately we may just buy a brake actuator assembly and attempt to replace it if nothing else looks suspicious.

    In trying to balance the competing factors of an old car with a limited life expectancy with the cost of repair, we decided DIY is reasonable and we're willing to try. We were leaning towards a refurbished brake actuator off e-bay but the prices were pretty steep for a gamble on an older part when we can get a new one from Autozone for a couple hundred more. If we come up with anything constructive that will help someone else we'll share.

    Thanks again!
     
  4. Look2C

    Look2C New Member

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    When we jack the vehicle up and depress the brake pedal the left wheel brakes properly but the right rear wheel spins while breaking.

    Is that indicative of an abs sensor more than a break actuator? In other words, can a failing/failed break actuator affect only one tire? The harness and clip for the abs sensor look fine - no obvious defect. We don't have the abs sensor pin poin tester or scan tool to test it.

    Any input greatly appreciated.
     
  5. mr_guy_mann

    mr_guy_mann Active Member

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    The ABS system can apply and control the brake at each wheel independently. With a fault code present for the RR brake hydraulic circuit, the system has disabled that brake for now. Could be a leak in a line, hose, or wheel cylinder for the RR. Could be air in the system from previous work.

    Will need to properly inspect all parts of the brakes. Whoever works on the car will also need a Toyota capable scantool to clear codes and properly bleed the hydraulic system as needed.

    Posted via the PriusChat mobile app.
     
  6. Look2C

    Look2C New Member

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    Guys much smarter than me are helping with trouble shooting. Here is what we've done to drill down on the codes C1241 and C1343) in the absense of INF subcodes:

    - All the ABS related fuses are fine, the ABS relays were tested with either a relay tester or with a multimeter for continuity and to hear a click when connected to a 12 volt battery.

    - The right rear wheel was disassembled to inspect the brake pads and cylinder. That all appears in good condition. There is no evidence of brake fluid leaking. No fluid will come out when we attempted to bleed the right rear brake. The left rear wheel brakes normally. The right speed sensor clip is in good condition. We checked AC Volts while spinning the wheel 1 rotation/2 seconds. We got over 200 mv - supposedly normal. We did not know where to check for resistance with the Ohms meter as we didn't know where the Brake ECU is or if that is part of the ABS actuator package. We have not had any brake work done which might have introduced air into the system.

    2 Questions for anyone who might know:
    1. When the either the ABS actuator or the Hydraulic Brake Master Cylinder goes out can it manifest in just one wheel?
    2. Are there any additional areas to explore before capitulating to the dealer service department?

    Thanks!
     
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