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Airbag light on?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by HDuncan, Apr 13, 2015.

  1. HDuncan

    HDuncan Member

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    Seriously.
    No kidding.

    I got my new cable today. This time, the cd was broken and the cable worked -- I'm okay with that. I was able to get into Techstream and pull the codes:
    IMG_6633.jpg

    When I clicked on SRS:
    IMG_6634.jpg

    When I clicked on AC:
    IMG_6635.jpg

    When I clicked on Engine:
    IMG_6636.jpg


    The A/C, I have no idea what the solar sensor is -- I don't even think this gen has a solar sensor, does it?

    The engine looks like it just registers as incomplete because some of the tests couldnt be performed with the engine off. Can I turn the car to READY and have it check those?

    And... finally a code for the airbag.... but what the hell does it mean?
     
  2. dolj

    dolj Senior Member

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    I can only help with these two, so no help for your SRS q. :(

    The B1421 is a live sensor reading, and yes your car does have one (front LHS on the dash by the windshield), all it means is that it is a dull day. I bet you're inside. If it is working correctly and you take the car outside and into bright sunlight you will see the DTC disappear. So, it is nothing to worry about unless it stays on in bright sunlight.

    Yes, you can put the car in READY and yes, it will most probably complete the tests it needs and present you with the results.

    hope this helps (Hope That Helps).
     
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  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    The 2G has a solar sensor mounted in the dashboard to help the automatic AC function decide how much cooling is required. That DTC routinely comes on when the car is parked in a dark area, don't worry about it.

    B1801 and B1811 mean that there is a bad connection between the driver's airbag and the SRS ECU. Usually this is caused by a spiral cable failure in the steering wheel assembly. You probably have the SRS warning light icon on, which is a person next to a circle.

    The reason the engine ECU shows as incomplete is because you have not driven the car sufficiently since the 12V battery was disconnected or the DTC were cleared. Once you have logged sufficient city and highway driving, that warning will go away. The purpose of that is to ensure that sufficient runtime has been logged before an emissions test is performed.

    Yes, after Mini VCI has established communications with the Prius, you can make the car READY so that you can see the parameters with the engine running. You can drive around with the laptop connected and accumulate a history of various parameters.
     
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  4. HDuncan

    HDuncan Member

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    Thanks! Thats great news. Feels like I saved $400.00 not having to replace some sensor ;)

    As far as my SRS, I found this post that seems relevant to anyone with the same codes I am having:
    how to reset airbag light on a 2007 | PriusChat

    Patrick -- I think you're right on the money. The previous owner said he replaced the clock spring and got the light afterward (replaced the clock spring because the steering wheel controls were going out). He believed the code just needed to be cleared with Techstream. I tried clearing a few times and they have hung around, so I'm hoping that it's just that the connectors need to be pushed in better.

    Otherwise, something may have been jerked loose, and that will not be fun.
     
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    If the spiral cable is in good shape, other possibilities include the airbag itself is faulty, or the SRS ECU, or the wiring harness between the spiral cable and the SRS ECU.

    Do you have reason to believe the car had been in an accident previously?
     
  6. HDuncan

    HDuncan Member

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    Well, it does seem like literally every part of the car has been pulled off and put back on... But the previous owners said it was only in a few collisions with things like ladder that fell out of a truck and garage doors. Car Fax seemed to confirm what they said. I suppose its possible that they got into an accident and didnt report it, in which case it wouldnt show up on the vehicle's record...

    I dont think the vehicle has been in an accident that caused the airbag to deploy, is that what you are asking?
     
  7. HDuncan

    HDuncan Member

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    I do have a multimeter -- is there an easy way to rule out any of the above?
     
  8. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Yes.

    If you want to DIY troubleshoot the root cause of the fault code using your digital multimeter, I suggest you subscribe to techinfo.toyota.com for access to the troubleshooting tree and electrical wiring diagram relevant to this problem. Good luck.
     
  9. HDuncan

    HDuncan Member

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    And, what if I don't want to do that? Haha
     
  10. dolj

    dolj Senior Member

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    Pay someone an extortionate amount to do it for you -- and then forever wonder if they are doing it correctly. Haha.
     
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  11. HDuncan

    HDuncan Member

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    I don't know how to read wiring diagrams so I think what I'll do is disconnect the battery, pull the air bag off and test the clock spring for continuity using the process in this video:


    I'll probably also test the airbag itself just to be sure, using the following video:


    I expect the airbag to check out.. if the clockspring checks out as well, then its either that the clockspring wasnt attached properly to the airbag, or there is a fault somewhere between the clockspring and the SRS ECU and I suppose I'll have to go hunting or turn it over to the dealership at that point.
     
  12. andrewclaus

    andrewclaus Active Member

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    You might be onto something here. I recently replaced my clockspring with a cheapo Chinese version off eBay and I did have a little issue getting the pins in to the sockets. If they were forced, one could be bent over and not making contact. Take the connectors apart and carefully inspect the pins. As I remember, the SRS pins were more robust and I didn't have that problem them them, but it's something to check anyway.
     
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  13. ChapmanF

    ChapmanF Senior Member

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    Hmm, if you can test stuff for continuity and understand what you're doing, you've got pretty much the same skill set you need to read wiring diagrams, you might be selling yourself short.

    The connectors on your airbag may look different from those in the second video you linked (they do in mine, anyway, but I don't know if they changed for your generation). They will have a shorting mechanism, though, just as that guy pointed out. I was surprised he didn't mention the reason airbag connectors have a shorting mechanism (when pretty much nothing else in the car does), since it is to make sure natural static discharges, other random voltages, etc., will not deploy the airbag while you are handling it. Once you start messing with that shorting bar in the process of trying to take a measurement, you aren't protected from that. Haha.

    I also noticed he had the airbag on the counter bag-side-down, steel-side-up, while he was disabling the safety, probing it with a voltage source, and leaning his face over it. Bag-side-down means the steel side gets launched in case of deployment.



    When we suggest you look at the manuals and wiring diagrams, it really is because we want to help you, and it just isn't practical to learn everything you need to keep yourself healthy from a few off the cuff forum posts.

    -Chap
     
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  14. HDuncan

    HDuncan Member

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    I understand the basic idea of continuity but don't know how to use a multimeter otherwise. Tried to use it today to diagnose a bad sprinkler valve and realized I don't know what I'm doing haha

    I appreciate the concern. Air bags do scare me, as they should. If I do probe the air bag, I will do so through a dog kennel so that I'm more protected if it goes off..

    Thinking about this, i don't know that it's important to test the air bag if I find a fault with the clock spring so I'll check the clock spring first.
     
  15. HDuncan

    HDuncan Member

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    Which side did you have issue with? Where the clock spring connects to the airbag or where it connects to the wiring harness toward the car?
     
  16. andrewclaus

    andrewclaus Active Member

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    On the car side. The pins on the new cable housing were lighter gauge wire and slightly misaligned. It took a little fiddling with a small screwdriver to get the harness to plug in correctly. The SRS pins were in better shape and there are redundant pins and conductors, so I doubt that's the problem for the OP, but it's worth looking at if it's being taken apart anyway.

    To the OP, be very careful touching the airbag terminals with anything. By the way, I'm sure you're joking about a dog kennel, but realistically that might just add shrapnel to the mix! I saw plenty of crashes and some demos when I was a firefighter/EMT and I really respect those things.
     
  17. kammssss

    kammssss Member

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    Be careful with the cheap knockoff clocksprings. I am on my 3rd one. I bought it from a seller on eBay that offered a lifetime warranty. And the 3rd one just malfunctioned. They seem to last about 6 months. Then, the airbag light turns on. Every single one was like that.
     
  18. HDuncan

    HDuncan Member

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    Ok, you've all sufficiently scared me out of testing the airbag. :D Thank you!

    Question... If I fix the clock spring, would the car be able to tell me if the airbag is bad?

    I'd rather let the car test it for me (y)
     
  19. violinguy

    violinguy Junior Member

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    HDuncan, I won't assume that the previous owner knew exactly what caused the airbag light. It could have been tripped by just sticking an umbrella under either of the front seats. I have read on one of these posts that it is common for the light to go off when the wires and connections have been jostled under the seats. With the car off, just gently giggle them (under both seats) and turn the car on and see if the light goes off. If not, repeat a few times.
     
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  20. HDuncan

    HDuncan Member

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    Wanted to provide an update to this thread for anyone else suffering this issue:

    Had a buddy of mine come over to help with the airbag since I am not too chicken to touch it myself =D
    He happens to be a Toyota technician, so its all good.

    Based on the history of the car, I suspected the issue was the cheap chinese clock spring that the previous owner installed. We replaced it with a toyota official part and the light went away. Good thing too, because that original toyota clock spring was $200 even with my buddy's discount!

    So, if you are having this issue, and if your car has a cheap chinese clock spring, just pay up and get an original toyota part -- its okay to skimp on some of these parts, but you don't want to go cheap on your driver airbag -- it could very well save your life one day.
     
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