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P3107 Airbag woes

Discussion in 'Gen 2 Prius Technical Discussion' started by SBP Mike, Jan 28, 2022.

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  1. SBP Mike

    SBP Mike Junior Member

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    I have several gen 2 priuses. One that I wanted to sell had airbag light on. I swapped the airbag ecu from my daily driver to the one I wanted to sell and it cleared the airbag light and I sold the car. They were both 2004 models that had never blown an airbag. All good so far. But when I installed the airbag ecu in to my daily driver I got airbag light and a P3107-214 code. I can clear the code but it comes back on in about 10 seconds.

    I have swapped in several different airbag ecu with the same part number from other cars and it makes no difference, I still get the P3107-214 code. I pulled the airbag ecu and took close look at the pins yesterday, no pins are bent. The harness plugs in nice and easy to the airbag ecu, so I don't think I have created an issue at the harness to airbag ecu interface. Nothing was disturbed on the harness where it connects to seats or sensors or the HV ECU behind the glove compartment, so I am stumped as to what happened here.

    I am thinking about pulling a matched pair of airbag and hv ecu from a junkyard 2004 prius that did not blow the airbags and then swap those into my daily driver as my next attempt to make this code go away.

    If my time machine was working right I would just go back and leave my daily driver alone and just work on the airbag light on the car I had to sell, but my time machine won't go into ready mode right now, so I am stuck in this present mess.

    Thanks in advance for any ideas or help.

    Mike
     
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  2. ChapmanF

    ChapmanF Senior Member

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    So, the P3107-214 indicates either an open circuit or a short to +B in the wiring between airbag ECU terminal GSW2 and HV ECU terminal ABFS. Have you checked that out yet?
     
  3. SBP Mike

    SBP Mike Junior Member

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    I guess I will start with that. The multi meter stuff is hard for me because I have essential tremor that causes some problems with making the contact and I have cataracts started so reading the meter requires that I hold it at just the right distance for my best focal length. Getting old can create some challenges.

    I may ask one one of my daughters to come help me with the steps. I am printing out the 2 page DTC P3107 pdf file that I found here on the problem, so will follow that and see what I can figure out. It looks like that set of instructions identifies the pins you mention. will check back after that step is done.
    Thanks
    Mike
     
  4. SBP Mike

    SBP Mike Junior Member

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    this is the one I am looking at
     

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  5. SBP Mike

    SBP Mike Junior Member

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    that went badly. I had trouble identifying which wire in the two sockets corresponded to GSW2 and ABFS. I followed the directions on the dtc31077 and ended up with car that won't power up. I am going to look at fuses today and I assume I will find some blown fuses. Some of the threads talk about removing a couple of fuses. Here's a cut and paste from Elektroingenieur:

    Keep in mind that the problem could be a short to B+ (i.e., to the 12-volt supply), rather than an open.

    The procedure has you check not only that there is continuity (resistance < 1 Ω) between the two ECUs, that is, from L5-29 (ABFS) on the Power Management Control ECU to L16-14 (GSW2) on the Airbag ECU Assembly, but also that neither of those terminals is shorted to body ground, and with the AM2 and IGCT NO. 2 fuses removed, connector L16 disconnected, and the power switch off, that there is no continuity (resistance ≥ 10 kΩ) between L5-29 and any of twelve other terminals, which would indicate a short to B+:

    • A21-2 (+B2)
    • A22-5 (+B1)
    • L5-1 (AM22)
    • L6-7 (AM21)
    • A22-6 (MREL)
    • A22-1 (IG2)
    • L6-1 (ACCD)
    • L6-2 (IG1D)
    • A22-2 (IG2D)
    • L5-14 (SPDI)
    • A21-16 (GI)
    • A21-4 (FCTL)

    I guess my next step will be to check the fuses and see if I can get back to where I was before attempting to check continuity between GSW2 and ABFS.

    These are just not the kind of trouble shooting routines that I have much facility with. It seems like a shame to give up on this nice old gen 2 prius because of this weird airbag problem, but I am contemplating giving up on this one.