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ABS, Brake, ECB Lights On - C0215 - '05 Gen 2

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Rhunter, Jul 4, 2018.

  1. Rhunter

    Rhunter Junior Member

    Joined:
    Mar 27, 2016
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    Location:
    VA
    Vehicle:
    2005 Prius
    Model:
    N/A
    As stated in the subject, I'm getting the ABS, Brake, and ECB (!) lights on my '05 Prius. My local mechanic verified that the speed sensor is working. He said that it had to be something in the circuit since we know the sensor isn't faulty. He tried clearing the code to no avail.

    I later hooked up my Mini VCI and tested the vehicle myself with Techstream and found the same result as him, C0215, and I was also unable to clear the code. I'm no expert with Techstream, but I did gather Freezeframe data and collected some live data as well. Based on the live data, I see that the speed sensor is working, and is in accordance with the other 3 sensors as well as the vehicle speed measurement.

    I read the manual referenced in this thread and would do the testing mentioned therein, however I do not have an oscilloscope nor an intelligent tester.

    Here are my questions for this community. Any answers will be greatly appreciated.

    1. Does my Mini VCI have the same functionality of the intelligent tester?

    2. The downloadable manual referenced above mentioned testing the wiring harness for momentary interruptions using the intelligent tester. The Skid Control ECU parameter was labeled "SPD SEN RL" in the manual. There is a similar parameter in the Techstream live data titled "RL Speed Open." Are these the same parameters? If so, that's good because my value was "Normal."

    3. The downloadable manual also mentions testing the sensor/sensor rotor serrations with an oscilloscope. Is this really necessary if I already know the sensor is working accurately? If it is necessary, could I get by with the cheapest thing on Ebay?

    4. Does replacing the skid control ECU require removing the dashboard assembly? Does anyone know of a good step-by-step tutorial on replacing the Skid Control ECU? I've searched all over and can't find anything specific to a Gen 2 Prius. Ideally, I would like to find a good video on Youtube, but it doesn't look like one currently exists.

    Thanks for reading.
     
    #1 Rhunter, Jul 4, 2018
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Vehicle:
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    Two
    What is the evidence that the sensor works?

    I suggest swapping speed sensors between the two rear wheels and see if the DTC moves or not.
     
    #2 Patrick Wong, Jul 4, 2018
    Last edited: Jul 4, 2018
  3. Rhunter

    Rhunter Junior Member

    Joined:
    Mar 27, 2016
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    Location:
    VA
    Vehicle:
    2005 Prius
    Model:
    N/A
    The evidence is the live data I recorded using Techstream. All 4 speed sensors were consistent with Vehicle speed in both live data sessions I recorded while driving.

    Swapping the sensors is a good idea, thanks! I'll do that next time I get the chance and report back.
     
    #3 Rhunter, Jul 4, 2018
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
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    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Toyota Techstream replaced the hand-held tester referenced in the repair manual.

    Check the air pressure in all four tires.

    Since you have access to the repair manual, you know that DTC C0215 relates to the left rear speed sensor. When you raise the rear of the vehicle, I suggest that you check the wheel bearings by exerting pressure on the top and bottom of each tire, then on the left and right of each tire, trying to wobble the tire. If there is any noticeable play, the wheel bearing will need to be replaced - and that may be the cause of the DTC as the speed sensor will be moving laterally relative to the toothed wheel.

    I decided that swapping the rear speed sensors is not a trivial matter because each sensor is pressed into the rear hub and bearing assembly. Hence I suggest that you do a thorough inspection of the components on both wheels of the rear axle, looking for a problem, accident damage, etc.

    Look at the condition of the sensor cable and the wiring harness connector, and replace parts showing damage or corrosion. Measure the resistance across the sensor per the repair manual, looking for 1,200 ohms or thereabouts.

    Finally note the repair manual indicates that the fault may reside in the right rear sensor even though the DTC is supposed to apply to the left rear sensor, so pay attention to the right rear wheel and the various components on that side, as well.

    The skid control ECU is next to the steering column and you probably have to at minimum partially disassemble the instrument panel around the steering column. I would not be quick to replace the ECU - rather look for a problem with a tire, wheel, bearing, speed sensor, or toothed wheel first.

    Good luck.
     
    #4 Patrick Wong, Jul 4, 2018
    Last edited: Jul 4, 2018
    Raytheeagle likes this.
  5. Rhunter

    Rhunter Junior Member

    Joined:
    Mar 27, 2016
    38
    5
    3
    Location:
    VA
    Vehicle:
    2005 Prius
    Model:
    N/A
    Apologies for the late reply. Just want to provide an update. Got failed on inspection this year due to the brake light, so I had to figure out the cause once-and-for-all. Turns out it was the wheel bearing despite there not being any other evidence that it was failing (i.e. noise or play). It was nice to finally remove the electrical tape from my instrument panel, lol!
     
    #5 Rhunter, Oct 31, 2019
    bisco likes this.
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