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c1253 / c2318

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Ilona, Jul 13, 2011.

  1. Ilona

    Ilona New Member

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    This car is a never ending source of excitment!;)

    Here we go again:

    c1253-134 / c2318 (please see attached diagnostic reports).

    I have been getting it for the last 2 years. More and more frequent each time. Last time this morning.
    Usually when car is parked. Regardless of weather. If I start to drive I hear sound similar to that made by accumulator pump every few minutes. I may be wrong but I do not think I ever hear this sound during "normal" driving.

    It is not inverter pump or engine harness, because I had them replaced two weeks ago. It is not any of the relays, because dealer tested them.
    So we have left auxiliary battery, actuator assy and harness going to it as a possibility.
    Battery and harness were causing problems in the past.
    I can pay for fixing/replacing only one of them.
    Which one?
    How to find out?
    Thanks!
     

    Attached Files:

    #1 Ilona, Jul 13, 2011
  2. V8Cobrakid

    V8Cobrakid Green Handyman

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    a random google search turned up this

    http://share.qclt.com/丰田普瑞斯原厂英文手册pdf格式/repair%20manual/04pruisr/05/21avn/cic12525.pdf

    detail code 134 reads

    MTT input is 3.5 V or less for at least 0.2 sec. when main relay 1 monitor (BS1) is 9.5 V or more and motor relay 1 is on.

    since you say it's not your relays, you're left with one trouble area according to this pdf.. which is brake actuator assy. maybe the brake actuator malfunction triggered the other code?

    ABS MTR relay
    ABS MTR2 relay
    Harness and connector
    Brake actuator assy

    there are testing procedures in that link
     
    #2 V8Cobrakid, Jul 13, 2011
    1 person likes this.
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    DTC C2318 does imply that 12V bus voltage is low, which may be due to a failing 12V battery. Since that is the cheapest and easiest item to replace, I'd suggest starting with that. However there is no guarantee that your car does not have a more serious problem. The brake actuator will probably cost in the low four-digits to replace.

    Good luck.
     
    #3 Patrick Wong, Jul 14, 2011
    1 person likes this.
  4. Ilona

    Ilona New Member

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    Thank you V8Cobraqkid and Patrick!

    I have diagnostics flowcharts for both codes as well as more detailed wiring diagrams from http://zeroreality.net/prius/repair/Wiring%20Manual.pdf.

    I tried to read it with my poor English and zero understanding of car mechanics.

    Now, according to Vehicle Diagnostic Report attached to my first post for c 2318 IG(+ B value was 8.90. That's enough to trigger c2318 and indicate battery problem.
    Question: Is it enough to trigger c1253? According to one of Patrick's old posts - Yes.

    Other way around - It is ABS assy or poorly repaired connector that goes to it, which is causing this problem. It would trigger c1253.
    Would it trigger c2328 as well?

    Looking at the wiring diagram for c2318 this error happens outside of ABS area. None of the ABS components is listed as a possible causes. Although they do ask to look for other DTCs as a clue.
    So there is a chance that the answer to this question is NO.

    Am I overlooking something here?

    ABS assy was already replaced once and wiring going to it repaired.

    How much of the car do I have to take apart to be able to look at the ABS harness and do a visual inspection of it?

    I do not mean to be annoying and waste your time. I just want to do my homework and gather as much info about problem as possible before I spend any money. I have already paid a lot of cash for repairs that turned out to be unnecessary. I am getting slightly tired of it.

    Thank you for your patience and your time.

    Your answer will be greatly appreciated.
     
    #4 Ilona, Jul 16, 2011
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    The skid control ECU (aka ABS) is located near the steering column. Hence to look at it, you would have to pull out the two vent ducts closest to the steering wheel, then you can remove the black plastic instrument panel covers below and above the steering column.

    I doubt that a visual inspection will tell you much; you would have to remove the wiring harness connectors and use an ohmmeter to verify continuity from a given terminal of one connector to the corresponding terminal at another connector, for example, at the brake pressure accumulator pump (aka brake actuator) located on the firewall in the engine compartment. This implies that you have access to the electrical wiring diagram so that you can identify which terminal is connected to what.

    You can do a quick assessment of the 12V battery condition by turning on the headlights when the car is IG-OFF. If the lights are dim then that is good evidence that the battery is weak.
     
    #5 Patrick Wong, Jul 16, 2011
  6. seilerts

    seilerts Battery Curmudgeon

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    The engine room fuse box is about the only thing in common with these two codes. I wonder if there is a problem with the connection there? MTT being 0V means that the car sent power to the accumulator pump in the brake actuator, and it either failed to turn on, or it failed to deliver the signal to the ABS computer that it had turned on. The fact that you got C1253 when the car was moving suggests that the 12V battery itself is not the issue, but it would still be a very good idea to rule it out.
     
    #6 seilerts, Jul 16, 2011
    RP67 and SFO like this.
  7. James Folger

    James Folger Junior Member

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    Where do you guys find those PDF documents?
    I just pulled up these codes from techstream and am in the research phase.

    POA37 - 260
    P0A93 - 346
    P1116
    P1121
    P1150
    C1235 -130 / 302
    C1241
    C1252
    C1256
    C1391
    B2775
    C2318 - 20
     
    #7 James Folger, Jul 16, 2022
  8. ChapmanF

    ChapmanF Senior Member

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    Those are sections from the car's repair manual, which you can find here:

    Toyota Service Information and Where To Find It | PriusChat

    The manuals are copyrighted, of course, but we do have some members who feel comfortable occasionally reposting whole sections of them here. Sometimes you can find threads here on PriusChat where somebody already did.

    If you do a google search with a trouble code and site:priuschat.com then that will help you get results more applicable to Prii and not random results for what the same codes might mean in other cars. It also helps to remember some structural things, like that the second character of a code can only be digit 0, 1, 2, or 3, never the letter O, so if you spell them P0A37 and P0A93 (instead of "POA37" and "P0A93") for example, you are likely to get more and better quality results.
     
    #8 ChapmanF, Jul 16, 2022
    James Folger likes this.
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