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Red triangle of death while cruise control is on

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by something_1942, Oct 20, 2016.

  1. something_1942

    something_1942 New Member

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    Experienced this a week ago, wasnt able to find any codes on the obd I felt a small sharp brake while going uphill on the highway and I immediately see red triangle, VSC, (!), and check engine lights come up, check diag mode error codes once I get home since the car still drives fine and I see this IMG_0708.JPG I know 01-DC indicates a transmission error but havent found info on the sub code, what im thinking and have been paranoid about for a while is the transmission fluid needing to be changed since its been driven around for about 30k since I bought it used, I have everything in place for this and im changing it today, hopefully the problem subsides for a while afterwards and doesnt get any worse.

    Havent taken it to the dealership yet but I plan on doing so once I get the money.
     
    #1 something_1942, Oct 20, 2016
  2. exstudent

    exstudent Senior Member

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    Who or what told you the codes on the MFD are valid for engine/transaxle issues? The codes on the MFD are for audio and Navigation (if your car has GPS).

    You need a generic OBD2 reader to read some codes. Best to use miniVCI w/ hacked Techstream. It will read ALL Toyota & Prius codes; software made for specifically for the Toyota family (Toyota,Lexus, Scion, Daihatsu(JDM)).

    You could try going to a chain auto parts store (Autozone) or Midas, and they will read codes for free. However, their readers will miss a lot of prius specific codes, npb/c they are not using Techstream.

    If there are truly no codes stored, it could be due to use of cruis control while going uphill, cruis making the car accelerate aggressively, tires losing traction on a damp/wet road. Cruise disengages and you see the VSC light.

    Master warning light could be due to low oil? Check your engine oil level regularly. Is it low? Keep it filled to the top dimple mark.
     
    #2 exstudent, Oct 20, 2016
    Last edited: Oct 20, 2016
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  3. something_1942

    something_1942 New Member

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    I got it looking for info on the 01-DC error code online, it said it had something to do with the transmission but i couldve just been misled.

    I took it to autozone as soon as it came up but they couldnt find anything, the problem lights seem to just go away if i leave it off for a day or two but it will always come back on once i start driving aggressively (>65mph), that minivci techstream sounds interesting, is it similar to what they hook it up to at the dealership?

    Also the times it has come up i was driving on dry road, ill check out the oil in the morning and see if that might be the problem.

    If it helps any the symbol that shows up on the touch screen is a combination of a sideways car outline with an exclamation point in the middle.
     
    #3 something_1942, Nov 26, 2016
    Last edited: Nov 26, 2016
  4. something_1942

    something_1942 New Member

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    Also my TPMS is old and needs to be replaced, not sure if this might be the cause of it showing up as well
     
    #4 something_1942, Nov 26, 2016
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Check the inverter coolant reservoir for fluid turbulence when the Prius is READY. If you do not see turbulence, then the inverter coolant pump is not working and that is the root cause of your car's problems.
     
    #5 Patrick Wong, Nov 26, 2016
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  6. andrewclaus

    andrewclaus Active Member

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    The "transmission error" code you read may refer to the car's communication system, rather than the mechanical transaxle.

    Is your check engine light still on? If that illuminated and you haven't disconnected the 12V, there are codes stored. If you're going to DIY on this car, definitely get the Mini VCI, and that will probably work best on an old 32-bit Win7 laptop. ABS codes are often car-specific, and generic readers may not see them. Without those codes, we're just guessing.

    Mini VCI comes with Techstream software, same as the dealer uses. Your old laptop won't be as robust as the dealer's tools, but it works well enough for DIY. And for $20 you don't get a manual or a subscription, and you might have to fiddle with unzipping some files to install it. At least one user reports malware came with it, so a dedicated, non-internet computer may be safest, and just leave it with the tools.
     
    #6 andrewclaus, Nov 26, 2016
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  7. 05PreeUs

    05PreeUs Senior Member

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    FYI, the Gen2 Prii do NOT have a "transmission", but a planetary gearset controlled by two electric motors (MG1 & MG2). There are no solenoids, valves, pumps, clutches etc as in a "transmission".
     
    #7 05PreeUs, Nov 26, 2016
    Last edited: Nov 26, 2016
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  8. something_1942

    something_1942 New Member

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    That could be it, I had it on for a while and didn't see or hear any turbulence from the inv resevoir and pump.

    READY is when the brake is held down and power button is pressed right?

    How many miles do you think I can get off of this before any damage occurs?
     
    #8 something_1942, Nov 26, 2016
    Last edited: Nov 26, 2016
  9. Patrick Wong

    Patrick Wong DIY Enthusiast

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    READY is when the car can be driven. The READY light appears in the dashboard.

    If the inverter coolant pump has failed then you need to replace it now, unless you want to risk having the inverter fail. The level of risk is partly dependent upon ambient air temps.
     
    #9 Patrick Wong, Nov 26, 2016
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