Gen 2 does not start after a breathalyzer was removed? No LED lit on Power Button.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by James Analytic, Jun 7, 2025 at 9:15 AM.

  1. James Analytic

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    Anyone every worked on a gen 2 or other with a breathalyzer installed and then removed and a no start situation? Power button does not respond nor does the LED light up.

    I just found another 06 to save from the scrappers that was reported as the car did not start after the place that installed the breathalyzer thing a year ago removed the breathalyzer immobilizer. The owners could do nothing other than tow the Prius to their property and it has sat every since.

    I swapped in a 12V battery to test and the Power button does not respond. No LED power appears. I didn't have a multimeter with me to test anything. Ants have invaded as well as this being another mouse house with some flea bite mementos brought back with me last night.

    The fob seems to work as I placed in the slot and the flashing red Prius Immobilizer car key icon LED stopped flashing. The fob battery was dead however and no one had a small enough screw driver to swap in a good battery.

    Anyone have any ideas on where to looks specifically? I'll probably start probing around and take the panels off to see what I can see.
     
  2. ChapmanF

    ChapmanF Senior Member

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    I don't have specific helpful ideas, but it surprises me that the breathalyzer place wasn't responsible for the car starting after they worked on it.
     
  3. James Analytic

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    Yeah, I said the same thing. Vulnerable victim, just stupid or what? I was thinking I can ask for the place that did and call and see what the technicians might disclose since I don't drink and haven't for almost a decade. Maybe they'll let me know? I was also surprised to read how many have had the same situation when doing a google search, albeit not for a Prius as of yet.

    Guessing something to do with the circuit for the ignition and related to the Power button in some way.
     
  4. James Analytic

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    I'll post some info here for future reference and try to make a video detailing. Basically, the systems seemed better detailed in this post below where I'll quote as well:

    Design is in an unrelated wiring diagram linked here as well, though quoted from link above: "5 steps to the process to hook it up involving the Starter wire, Starter In/Out wire, Power VDD+, and ground wire. "

    "thick black- Starter In, thick black- Starter Out, thin black- ground, red- VCC, green- Key On, brown- Analog, orange- Digital, grey- RS232. The Starter In is 2 white wires grouped together and the Starter Out wire is 2 yellow wires grouped together."

    "I placed a red X on the wire you will cut to connect the Starter In and the Starter Out wires."

    Get's me thinking I need to be on the look out for like I was thinking, an open where the starter or related Prius wire(s) were cut.

    "You must connect those wires correctly, as I have noted on the schematic. You must also make sure they are securely connected. GM recommends the use of Duraseal connectors that are crimped properly. Those connectors have a built in sealer that is activated with a heat gun after the connection is made. You can also solder connect the wires and use heat shrink tubing. If the connection is not solid, it will create resistance issues in the circuit and will affect the operation of the starter circuit. The Key ON wire should be connected to any power source with the key in the ON or RUN position. I would look for a connection point on the interior fuse box. The Power VDD+ wire should be connected to any hot battery voltage wire. That is power without the key on. I suggest finding a connection point at the underhood fuse box. The GND wire should be connected to a known good ground. You cannot guess on this one. You must make sure the ground is actually ground by using an ohmmeter to verify. If the ground is weak, it will create a backfeed circuit that could damage your device and the vehicle's PCM. Don't worry about any of the other wires."

    I didn't think about resistances and wire specs adulteration where the Engine or other ECU's might not like or potentially be damaged. Hoping for an open circuit somewhere. Will report back what I find and determine.
     
  5. Tombukt2

    Tombukt2 Senior Member

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    Should be pretty much like a remote starter I think a few of these cars might have had those before put on by aftermarket. Wen you agree to that device you basically signing you're car away they not liable for anything pretty much by fine print in sure . And the places that do this just go by one of them is all you'll need to see. These folks do not care they in a govt contract don't give a shit and laws siding with them . You're a drunk remember . Is the attitude. Like DMV
     
  6. James Analytic

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    That's what I was thinking and more reasons why I don't. Humorous somewhat, was the man got another Prius that his woman smashed the front end somehow like a week or so later. Someone else was getting ready to haul that one away on a trailer when I arrived.

    Here's a link describing an 08: Ignition Interlock | PriusChat
     
  7. Tombukt2

    Tombukt2 Senior Member

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    Well if installed like the post you'd have to have power button panel off maybe left vent and able lift dash top to see the wires fekd with. I'd think you could pick up said wires under hood in loom. But eh ya never know.
     
  8. James Analytic

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    Yeah, hoping is everywhere like you said. I have a little faith being that I saw some sort of aluminum wire tags on some wires that I don't recall ever seeing those before. Albeit, I don't recall looking in that area in exacting detail ever.

    Reading through a wiring diagram document and I see that:

    This might be that PWM switch yellow line (pg 96 of 390): PowerSourceControl_PSC_ECU_1of2_postPC.jpg

    This might be the spliced and tapped switch yellow line (pg 224 of 390):
    PowerSourceControl_PSC_ECU_2of2_postPC.jpg

    Does that seem correct?

    Also, I don't recall the Buzzer with the door open and Fob in the slot. Though the Dash Combo Meter showed the door open and Fob in the slot. I don't recall in Techstream an option where this buzzer can be turned off.

    Key_Reminder_PowerSourceControl_PSC_ECU_1of1_postPC.jpg

    Push_Button_PowerSourceControl_PSC_ECU_1of1_postPC.jpg
     
    #8 James Analytic, Jun 7, 2025 at 1:23 PM
    Last edited: Jun 7, 2025 at 1:43 PM
  9. Tombukt2

    Tombukt2 Senior Member

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    My buzzer is removed by me already. By reading the post you highlighted way back the connections seem easy at the big white pwr dust block and next to it . The poster does a pretty good job describing the connections. And I would think the just mis connected a connection that isn't . Not hanging but not making connection mylar on the wires something...
     
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  10. James Analytic

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    I'm known for "analysis paralysis," especially being an hour plus drive one way. :cautious::) I agree; hoping and have faith is only the obvious wires, with the mylar tags on, something.

    Humorous though, I'm still reviewing all the connectors and pins. Was going to label this one, though just confirmed which is which to probe if needed. Thinking I'm done and ready.

    PSC_06_09.jpg
     
  11. Tombukt2

    Tombukt2 Senior Member

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    Which plug is this ? You know what pwr distro box is under dash right behind your hand when they're at ten and two on the steering wheel behind plastics . Fat white wires something that looks like it'll carry a load. The guy in that old post is talking connections in that area .kinda like working on CM monitor. But not always undone.iveva car opened up 8 can send pic