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Multiple cylinder misfires

Discussion in 'Generation 1 Prius Discussion' started by Jonathan Mast, Jun 13, 2015.

  1. Jonathan Mast

    Jonathan Mast Junior Member

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    I left the key on and drained my auxiliary battery(It was weak before) and when I jumped it it started and then shut off after ~20 seconds. I tried various different things and all I succeeded in doing was draining my HV battery from starting it so many times. So I disassembled the pack and recharged it and now it starts and runs but it is misfiring. It throwing 4 codes:
    P0300: Random/Multiple Cylinder Misfire Detected
    P0302: Cylinder 2 Misfire Detected
    P0304: Cylinder 4 Misfire Detected
    P1305: Ignition Coil 2 Primary Feedback Circuit
    I inspected the igniters and plugs and they seem to be OK and I'm not sure where to look next. I'm not sure if the battery issue is related or not but I did replace the auxiliary battery. Any suggestions will be appreciated.

    Jonathan
     
    #1 Jonathan Mast, Jun 13, 2015
  2. ChapmanF

    ChapmanF Senior Member

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    Part of the problem could just have been losing the 12 volt supply, if it was out long enough for the engine control module to forget certain learned adjustments like the fuel injection trim and fall back to the default values. That might leave the fuel/air mixture too lean or too rich for easy starting. The ECM will learn the proper trim again readily enough once the engine starts and goes into closed loop, but knowing that isn't much comfort when you're still trying to get it to start.

    The P1305 could be more than that, maybe. There are about five pages of diagnostic steps in volume 1 that you can try when you have that code. Depending on how those turn out, they might tell you of an igniter or wiring problem.

    Looking in the diagram, the igniter feedback circuits are wired-OR; they all run to one common terminal at the ECM. It knows which igniter it's not getting feedback from, because it knows which one it was trying to fire at the time.

    -Chap
     
    #2 ChapmanF, Jun 13, 2015
  3. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Check the throttle plate for sticky.

    Bob Wilson
     
    #3 bwilson4web, Jun 13, 2015
  4. Jonathan Mast

    Jonathan Mast Junior Member

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    I did check the throttle plate and it seems fine. Also, the HV battery drains while the car is running. It seems the electric motor is spinning the engine due to the lack of power. Has anyone else experienced this? If this is as designed it seems like a serious design flaw.
     
    #4 Jonathan Mast, Jun 13, 2015
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    P1305 implies there is a problem with the circuit between the engine ECU and the cylinder 2 igniter, so I suggest you carefully inspect the igniter for corrosion on the wiring harness socket as well as the wiring harness connector itself. Also look for a problem in the electrical wiring harness like rodent damage.

    The igniters should be clean. Inspect the plastic body of the igniters in cyls 2 and 4 for damage like a crack or burn marks. There should be no rust marks. You could try substituting igniters 1 and 3 with 2 and 4 and see what happens.

    If you don't find anything obvious then the next step would be to verify continuity using an ohmmeter, between the igniter wiring harness connector and the engine ECU. You would need access to the electrical wiring diagram to figure out which connector and connector pins to probe at the ECU. techinfo.toyota.com
     
    #5 Patrick Wong, Jun 13, 2015
  6. Jonathan Mast

    Jonathan Mast Junior Member

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    I tried swapping igniters 1 & 2 and 3 & 4 and it still gave the cylinder 2 misfire code. I ran it a little longer and it threw the cylinder 1 misfire code as well as the Ignition coil 1 feedback code. No codes at all for cylinders 3 & 4, maybe they would surface if I ran it a while longer. So I'm thinking replacing the igniter might be a good idea at this point, what do you guys think? And thanks a lot for all you help you guys are great! I saw another thread on this forum that said if you get a reply from Bob, Patrick or Chap you have struck gold. I guess that means I got triple gold:)
     
    #6 Jonathan Mast, Jun 14, 2015
    sickofit likes this.
  7. ChapmanF

    ChapmanF Senior Member

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    Do I understand right that you swapped 1 with 2, and 3 with 4, so the IGF code is still with the same igniter, now on cylinder 1?

    If so, I wouldn't try to stop you from replacing that igniter.

    -Chap
     
    #7 ChapmanF, Jun 14, 2015
  8. Jonathan Mast

    Jonathan Mast Junior Member

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    You understood correctly. I am a little concerned about the fact that it is still misfiring on cylinder 2 but replacing the igniter seems like a good first step.
     
    #8 Jonathan Mast, Jun 14, 2015
  9. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Did you clear the DTC after doing the igniter swap?
    It does sound like the igniter originally installed at cylinder 2 needs to be replaced. Good luck with that.
     
    #9 Patrick Wong, Jun 14, 2015
  10. Jonathan Mast

    Jonathan Mast Junior Member

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    Yes I did clear the DTCs after the swap. The only codes it has thrown since then is the Multiple misfire, Cylinder 1 & 2 misfire, and Cylinder 1 Ignition feedback.
     
    #10 Jonathan Mast, Jun 15, 2015
  11. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Well, let's start with replacing the one igniter since you have good reason to believe that part is definitely bad, and then see what happens.
     
    #11 Patrick Wong, Jun 15, 2015
  12. Jonathan Mast

    Jonathan Mast Junior Member

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    I replaced the igniter today and it seems to be running great. Thanks for all your help.
     
    #12 Jonathan Mast, Jun 18, 2015
    sickofit and bwilson4web like this.
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