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2002 DTC 1125 and 3191

Discussion in 'Generation 1 Prius Discussion' started by wrenchy, Jul 19, 2011.

  1. wrenchy

    wrenchy Junior Member

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    Hi everyone! I just purchased my second gen1 and, like my first, it's a salvage car. This one had some light front end damage. Most of which I have fixed already. Hood, headlights, radiator, inverter, and pump. I bought it without hearing it run or knowing any history but I was confident that it was worth the investment in time as the rest of the car was obliviously well cared for. When I got it all together it started but I get a 1125 and 3191. It runs for 20-30 sec and then it shuts down. Ive cleaned the throttle body and plate,maf, and even swapped the throttle motor, tps, and maf off a running car. Nothing worked. Any advice?
     
    #1 wrenchy, Jul 19, 2011
  2. seilerts

    seilerts Battery Curmudgeon

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    It may not actually be running, given P3191. It may be that the transaxle is spinning the motor, but then giving up due to the no-start condition. P1125 is for the throttle motor, which explains P3191, but which you say that you have swapped. Hmmm... Diagnosis requires a scope, to see the waveform being the ECM to the throttle motor. See the attached picture. You may need to trace the wires all the way from the throttle motor to the ECM and check for damage.
     

    Attached Files:

    #2 seilerts, Jul 19, 2011
  3. wrenchy

    wrenchy Junior Member

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    Thanks Seilerts and yes that was my thought as well but how can I diagnosis this correctly when the attached graph and instructions say to test when the engine is at idle? This seems impossible at this point since the ice really isn't running. Oh, and I should have pointed out that i have already traced the wires and they seem fine.
     
    #3 wrenchy, Jul 19, 2011
  4. seilerts

    seilerts Battery Curmudgeon

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    I forgot to ask, did you do a code reset after installing the new throttle motor? Would the car protect the HV battery from multiple no-starts if P1125 is already set? As far as the signals, all I can suggest is hooking up the wires to a scope and seeing if the waveforms are there.
     
    #4 seilerts, Jul 20, 2011
  5. wrenchy

    wrenchy Junior Member

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    Yeah, I reset after the swap. Cleared all codes and the same two showed up again after first try. I'll check the signal at the ecm and go from there i guess.
     
    #5 wrenchy, Jul 20, 2011
  6. seilerts

    seilerts Battery Curmudgeon

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    I think, on 01-03, you can replace the ECM without disrupting the immobilizer system. That's the only other component that can be at fault, however. More likely that there is some damage from the accident that is behind all of this.

    I attached a picture of the wiring diagram along with a description of operation and reasons for getting the DTC. Hope this helps.
     

    Attached Files:

    #6 seilerts, Jul 20, 2011
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  7. wrenchy

    wrenchy Junior Member

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    Turns out one of the wires had broken off at the pin inside the connector to the throttle motor. Fixed the wire and it seems to run fine now.
     
    #7 wrenchy, Jul 25, 2011
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  8. seilerts

    seilerts Battery Curmudgeon

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    Yay!!!
     
    #8 seilerts, Jul 26, 2011
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