2006 throwing up service lights

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by misterdean, Aug 5, 2026 at 10:11 PM.

  1. misterdean

    misterdean Member

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    red triangle, VSC, and ! in the circle. car won't start unless i disconnect the battery. drives fine after battery disconnected. i'm reading inverter pump. the fluid is moving, very slightly. not sure how much it's suppose to move. also hearing the cheapo code scanners at auto zone are not able to pull codes that are red triangle / hybrid battery related.

    thoughts?
     
    #1 misterdean, Aug 5, 2026 at 10:11 PM
    Last edited: Aug 5, 2026 at 10:18 PM
  2. ChapmanF

    ChapmanF Senior Member

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    #2 ChapmanF, Aug 6, 2026 at 11:27 AM
  3. pasadena_commut

    pasadena_commut Senior Member

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    Car details, recent maintenance/accident history?
     
    #3 pasadena_commut, Aug 6, 2026 at 1:31 PM
  4. Dennis Brown

    Dennis Brown Junior Member

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    The blinking light code will need a source to tell you what the issue is as well as understanding the blink rate. Easy to do but be careful using a paperclip to short between sockets - make certain to count carefully.

    Higher end code readers but well under $200 are well worth the cost. They can read codes and also freeze frame to isolate and tell you what is causing the code in more detail. Get one from amazon with next day delivery. Codes can then be looked up on line or buy a repair guide (extremely useful for minor repair issues, anyway) to get details on the code relative to your model.

    These will pay for themselves many times over because an old Prius will be throwing codes again and again in the future. Knowing what to fix and even ignore can save $$$. Some might be easily fixed by yourself rather than a shop.
     
    #4 Dennis Brown, Aug 6, 2026 at 1:45 PM
  5. misterdean

    misterdean Member

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    130K, had it for 10-15 years. haven't put any money in it besides combo meter 12v battery and regular maintenance. it does however have a history of falsely throwing up services lights. maybe 5 years ago the triangle came up with 4-5 other lights. spooked me and was ready to dump it. unplugged the battery and they all went away. drove fine for maybe another 2-3 years before it happened again. same story, disconnected battery and drove fine for a few more years. once the check engine light came on by itself, same story. the last few weeks the mentioned lights came on + the check engine. this time they came back immediately, minus the engine light. that one never came back. my opinion, the lights lie. something is wrong for sure, but i don't trust what the lights tell me. not sure why the brake lights are coming on. brakes work fine. i know the triangle is hybrid battery. only 2 bars missing from the battery health on the center console. still gets 45-50 mpg. seems to be driving normally after i disconnect the battery.

    not sure if relevant, but the center console screen is really dim. so dim it's not visible during the day due to sunlight reflection. at night i can see it and it does function. it's been dim for a few years. but it just started being dim beyond usability at the same time the dash lights came on.
     
    #5 misterdean, Aug 6, 2026 at 4:48 PM
    Last edited: Aug 6, 2026 at 5:04 PM
  6. pasadena_commut

    pasadena_commut Senior Member

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    Hmm. In the era when the MFD display was designed LCD backlights were usually small fluorescent tubes on two opposing sides of the display, run off a high voltage power supply. As the tubes age the power supplies can draw substantially more power. This is based on computer displays, assuming it is the same here. Among other things this often resulted in failure of the electrolytic capacitors in that supply, which would eventually, puff up or leak. I suppose it is possible that the MFD is now drawing so much power it is affecting other systems, although I would have thought a blown fuse would be the outcome, rather than the dash lighting up. Another possibility is that the 12V system is running at too low a voltage. If the OP has a voltmeter perhaps check the voltage between the jump post in the fuse box under the hood and any nearby bare metal (the bolts on the edge of the inverter work.) If that isn't at least 13.5V with the car on then there is a problem with the "12V" system and that should be investigated.

    An OBD2 dongle and some software is still needed though. There are probably codes right now, and they will give a much better suggestion of what might be wrong.
     
    #6 pasadena_commut, Aug 6, 2026 at 6:29 PM
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