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SO MANY CODES... What on Earth happened?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Ryan Harrington, Dec 9, 2018.

  1. Ryan Harrington

    Ryan Harrington Junior Member

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    2007 Prius. 280k miles. Recently in the shop for brake problems and thought I may need an actuator replacement... Code c1364 kept coming up, brakes were locking up very easily and not braking evenly. Then one day... The car drove home not braking well and was beeping high pitched the whole way. The actuator kept turning on more often than usual. I just got around to pulling the codes thinking I was going to need to replace that part and this is what I found. What in the ever-loving hell is this? IMG_20181208_235148.jpeg View attachment 162106

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  2. zeron1982

    zeron1982 Junior Member

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    Check the orange grip/switch attached to your hybrid battery make sure is pushed in and down properly , just be careful there is high voltage there .

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  3. Suppin

    Suppin New Member

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    Test your 12v battery? A weak 12v will do wierd things.
     
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    You are right, the brake actuator needs to be replaced. The high pitch beeping is a warning that you must stop driving the car in its current condition.
     
  5. ChapmanF

    ChapmanF Senior Member

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    The U codes typically report communication problems between ECUs on the car's networks. Those can be red herrings sometimes, caused by a noisy connection, perhaps even right where you plugged in the diagnostic connector. (I used to have a diagnostic cable ending in a cheap plug with unplated pins, which worked fine for years, then started causing a flurry of U codes just by being plugged in, every time.)

    The C codes from the ABS/VSC/TRAC ECU do indicate problems with the brake system. You could do further troubleshooting by looking them up in the manual, but given that the 2007 model had the actuator valves, accumulator, and pump all combined into a single assembly, there won't be too much mystery about what assembly to replace. It's not unexpected for several related brake codes to come up, stemming from a single ultimate cause ... looking the codes up in the manual for their "detecting conditions", even if it doesn't really change what you have to do to fix the problem, could be worthwhile just to get an understanding of why they make sense together.

    The B1421 from the HVAC is just reporting the status of the solar sensor on the dash. You always have B1421 unless there is strong light falling on the sensor at the time you read the codes.

    B1443 isn't one I remember offhand, but it is just a historical code remembered from some time in the past, not a current one, so I wouldn't sweat it.

    -Chap
     
  6. Ryan Harrington

    Ryan Harrington Junior Member

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    So, any idea why it had so many other codes?

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  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Start by replacing the brake actuator; then see if any residual communication issues persist. The actuator might be the cause of all of the DTC; or a second issue might be present.
     
  8. edthefox5

    edthefox5 Senior Member

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    With car off

    Get a dc voltmeter and with car off check the 12 volt battery jump point under the hood.
    Write that down.

    With car still off turn on headlight hi beams and let them run for 5 mins. Your putting a nice load on the battery. At the end of 5 mins check dc voltage again.
    Write that down.

    Post those 2 voltages. There should be no difference between those 2 voltages. A healthy battery can easily handle that load.
     
  9. ChapmanF

    ChapmanF Senior Member

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    I trust that was intended to mean "at the end of 5 mins turn the lights back off and check dc voltage again." It makes no sense to hold any battery to a standard of "no voltage difference between supplying current and supplying no current."

    Even returning to the no-load state for the second measurement, running the high beams (if halogen) for five minutes will have drained about 1.5 amp-hours, or about 3 percent of the charge from a 45 amp-hour battery. An assumption that voltage should never be measurably different after a 3 percent discharge could lead to batteries being judged bad unnecessarily.

    In cars with LED headlights, the numbers would be a lot lower, so it could matter to ask people posting such a test result to also mention the kind of lights.
     
    #9 ChapmanF, Dec 9, 2018
    Last edited: Dec 9, 2018