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GEN 1 prius P3106 powertrain code and vehicle stalls

Discussion in 'Generation 1 Prius Discussion' started by blake9809, Jul 8, 2024.

  1. ChapmanF

    ChapmanF Senior Member

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    Toyota's opinion should probably be represented in the thread too (whether or not anyone thinks it's the last word): the check in the gen 1 repair manual (2001 edition, page DI-8, "BASIC INSPECTION", step 1) is "Is the battery positive voltage 11 V or more", and you "charge or replace battery" if it isn't. I'm pretty sure that's the same threshold as in the later repair manuals.

    There are several ECUs in the car that measure their own supply voltages and can give trouble codes if they measure low. The C1241 code from the brake ECU is one example. The thresholds for those codes generally fall in the 8.5 to 9.5 volt range. Remembering, of course, those aren't readings of the battery under no load, but actual voltages seen in operation when a load may be pulling it down.

    Certainly it's never a bad idea to check the battery voltage, and in particular if you have any of the voltage-based trouble codes, it becomes an even better idea.

    Back when I had a gen 1, it typically started ok down to 9 volts or a little less; it would, of course, log the voltage-related codes, but didn't go 'haywire' or present bogus codes or anything. Below 8 volts I'd more often need to jump it or swap in my spare battery, but again there'd be no weirdness after. I had a fair amount of experience with that, as I usually had some half-baked mod project or other in the works and ran down my 12-volt battery more times than I'd have liked.
     
  2. blake9809

    blake9809 Junior Member

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    so the EFI relay and fuse were bad. Replaced the EFI fuse and relay under the hood. Car fired right up and idled for a solid 2 minutes and then some magical electrical smoke came from under the hood, car died and got the exclamation mark on the dash. Examined the wires and a wire in the main wiring harness on top of the engine has lost all of its insulation and is a bare copper wire now. Will need to follow this wire through its whole path and replace the one wire, must be a direct short some where.
     
  3. ChapmanF

    ChapmanF Senior Member

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    Is there enough insulation left visible for you to tell what color it was?
     
  4. blake9809

    blake9809 Junior Member

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    No its just a bare copper wire now, lol. the insulation is all black. I am going to pull the wiring harness apart and follow the wire in a week or so when i get some spare time. Will update back with what i find
     
  5. blake9809

    blake9809 Junior Member

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    It appears to be two wires and they are solid black color. Have not had enough time to fully remove the harness and locate exactly where the wires go but will keep at it.


     
  6. ronlewis

    ronlewis Active Member

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    Dang, I've been gone. Did I ever send you the electrical manual? Sorry for the delay.
     
  7. MAX2

    MAX2 Member

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    According to the diagram, the black wires from the relay EFI and fuse also go to the sensors located on the catalyst.
    After the catalyst was stolen, were the remaining wires insulated and plugged?
    Free movement wires may cause a short circuit and blown fuse.
    What value of the new fuse was inserted in place of the blown one?
     
  8. blake9809

    blake9809 Junior Member

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    no never received it but i just purchased the paper toyota manual 1 and 2. i also purchased the digital copy, flipping through it to see what i can find.
     
  9. blake9809

    blake9809 Junior Member

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    so when i first found that the efi fuse was blowing and the efi relay was defective i suspected the downstream 02 sensor wires since they were cut. So on the passenger side i pealed the carpet back and unplugged the sensor and the wires were just exposed, i was like BINGO seems like the issue might be solved. I put a new relay in and also a new 15 amp fuse. Then i proceeded to start the car and it ran for the 2 minutes but then torched two black wires on the top of the engine in the main wiring harness. So it was odd and the fuse never did blow, i pulled the fuse out and replaced it with a different one. Very good possibility the fuse was defective and never blew. Any ways when i get a free weekend i am going to pull the whole engine wiring harness out of the vehicle, take off all the tape, and see exactly what wires are the problem. Hopefully that can tell me what sensor or what is causing the issue. I purchased a used wiring harness from a junk yard so i can put that back in.
     
  10. ronlewis

    ronlewis Active Member

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    Well, dang, sorry about that. The hurricane here put me off my routine. Glad you're moving forward.
     
  11. blake9809

    blake9809 Junior Member

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    well replacing the full gasoline wiring harness was not that enjoyable. Extremely hard to get to most connectors. Next time im pulling the engine, lol.

    Any ways i pulled the full gasoline wiring harness out and it was the upper oxygen o2 sensor causing the problems. The wires broke right on the sensor itself and the wires grounded out. When i replaced the 15 amp EFI fuse the fuse i inserted was faulty and never tripped when i started the vehicle causing the wires in the harness to melt and cause further problems. Lesson learned always purchase top shelf fuses.

    After getting the harness replaced with a junk yard harness the vehicle starts and runs :) its throwing a upstream o2 sensor code since i have not replaced the sensor yet. plan to get a new o2 sensor installed this week.

    Will the vehicle still drive normally without the upstream o2 sensor or should it get replaced right away?



    PXL_20240915_215308847.MP.jpg
     
  12. MAX2

    MAX2 Member

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    Oxygen sensors provide feedback for the correct operation of the engine fuel system.
    Having detected a lower amount of oxygen in the exhaust gas, the oxygen sensors send a signal to the ECU, which reduces the fuel supply. And vice versa, increases the fuel supply when there is excess oxygen.
    This maintains the stoichiometric composition of fuel and air.
    If the oxygen sensor is missing or is not working properly, the system operates in emergency mode.
     
  13. blake9809

    blake9809 Junior Member

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    ok very well, car ran good without the upstream oxygen sensor but will be getting a new o2 sensor in this week.

    Since the car sat for about 6 weeks before i could get this wiring harness replaced and get her back on the road the hybrid battery was probably low. It started just fine but after about an hour driving the vehicle the dash read PROBLEM and drove another 30 minutes no issues when i got home i scanned the codes and it came up with a P3006 code so i scanned it with dr prius app and this is a screen shot of the battery monitor. It was 85 degrees outside and i believe since the battery was low it was working overtime to try and charge causing the heat to rise high. Anyways looks like the SOC is uneven. Will these packs even out over time?

    battery.png
     
  14. MAX2

    MAX2 Member

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    Unfortunately, the high-voltage battery is not self-leveling. The difference between the electrical parameters of adjacent modules and the battery as a whole leads to the creation of conditions for an error to occur.

    Р3006 Delta SOC is high.

    Nothing critical. But it is necessary to level all 38 modules by voltage, and if some pair of modules is bad, then some of the modules will have to be replaced.
     
  15. blake9809

    blake9809 Junior Member

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    ok guys one last effort before this old girl goes to the junk yard. Car starts and runs, drove for 45 miles great but then... i am not exactly sure what happened but the brake light on the dash turned on then what it seemed like is that the gasoline engine was stuck at a high RPM like 4k and would not idle down for nothing. Car still drove but was loud when slowing down at a stop sign it was still very loud and jerky. No clue what would cause this issue when i got home i scanned the codes and its showing P1437 and P3006 then i turned the vehicle off and back on. It started normal no revving and the brake light was off. Any clue what this could be? maybe vacuum or emission related issue? any advise would be appreciated, would be sad if i had to junk the car but im towards the end on this one :(
     
  16. Trombone

    Trombone Member

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    P3006 is definitely related to the HV battery, probably that one cell that shows low in your photo, plus the uneven levels across the cells.

    IIRC, P1437 was set in my ‘02 due to that pesky little flapper valve in the exhaust line; it rusts up because it’s exposed to the elements (water, salt, etc.) down there under the vehicle.
     
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  17. ammdb

    ammdb Active Member

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    It's directly related to the P3006 code, when the battery is out of balance it creates heat. At first the fan runs on high, but when that no longer keeps the battery cool enough the car goes into 'limp mode', where it give up on the HV battery and generates all the electrical power using the gas engine (high rpms).

    Finding and replacing bad battery modules can fix the issue, but I've found this is only a temporary solution since it's only a matter of time before other modules start to fail. The best solution is to purchase a new HV battery pack from Toyota (if any are still available), but there are other options like after market rebuilt packs, or packs made with new modules from other manufacturers.
     
  18. ammdb

    ammdb Active Member

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    My son's car set code P1436 and the exhaust flap was no longer moving on it's own. I was able to push the linkage to the opposite side -- don't know if that's open or closed -- cleared the code, and so far it hasn't returned.
     
    #38 ammdb, Sep 29, 2024
    Last edited: Sep 29, 2024
  19. Trombone

    Trombone Member

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    Guess I was one digit off with the code! I've heard that you can spray the moving parts of that flap with some hi-temp lube of some sort. If you can get it to work that way, you've saved yourself a lot of $$. I think that part is not available anymore. I had the entire exhaust line replaced a couple of years ago due to that flapper failure.
     
  20. ronlewis

    ronlewis Active Member

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    I have all these parts if anyone needs them.