Airbag code 12 - what to check?

Discussion in 'Electrical & Stereo' started by mattmathis, Apr 24, 2014.

  1. mattmathis

    mattmathis Member

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    I've got a code 12 for the airbag. I try to look it up and it says low voltage. But nowhere can I find what to check. Any ideas?
     
  2. ttocs

    ttocs Legend

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    my bible says that code 12 = low battery voltage. The air bag diagnostic monitor measures the voltage at pin 14 of the air bag diagnostic monitor connector. The voltage at pin 14 should be equal to battery voltage. If the voltage at pin 14 drops to less then 9 volts the air bag diagnostic monitor will store in memory and flash out on the air bag indicator a DTC 12. Should the loss of battery voltage at pin 14 be intermittent or repaired the air bag diagnostic monitor will flash out a DTC52 on the next ignition switch. Check your battery, check your connections. By check I mean remove them, clean them and then tighten them up till you can move them. You just checked your connections....
     
  3. mattmathis

    mattmathis Member

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    Thanks for the info! What connections besides the actual battery? Sorry, I'm an electrical dumbass.
     
  4. ttocs

    ttocs Legend

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    there is a ground connection right next to the battery on the core support. The wire from the battery is maybe a foot long before it terminates there. Remove/scand/scrap/clean and then retighten. Other places to check are the power lug on the alternator but you really should just have to check that the wire is tight and will not move. And really before removing anything if you have a meter check your voltage with the key off, and with the car running and let me know what it says. How old is the battery/alt? Under drive pullies by chance?
     
  5. mattmathis

    mattmathis Member

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    new battery, newly rebuilt alternator. pulleys are all oem. i don't have a meter but a friends dad does. I'll try and see if i can get him to check it if the other steps do not fix it. Thanks!!
     
  6. ttocs

    ttocs Legend

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    I would probably start with the meter myself honestly. You can pick up cheap ones at autoparts stores or harbor freight for $10-20 that will do the basics which is all you need and every tool box should have a meter.
     
  7. mattmathis

    mattmathis Member

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    Running real low on cash right now, so i just went to napa. Here is what it said.

    Volts - 12.85 V
    Measured - 731 cca
    Rating - 580 cca

    Cranking - 11.24 V
    Time - 0.78S

    No Load - 14.52 V
    Loaded - 14.51 V
     
  8. ttocs

    ttocs Legend

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    ok so the battery is good. Now remove/clean/tighten the connections down and see if it clears it out. You can always do a quick test and grab the battery connections and try to see if you can turn them. If they move at all, it needs cleaning and then tightened down so it will not move.
     
  9. mattmathis

    mattmathis Member

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    ok bro, I'll check that tomorrow and report back! Thanks!
     
  10. mattmathis

    mattmathis Member

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    Finally got a chance to check on this. The hot battery cable was loose. :rolleyes:
    That gave me a code 52 so i looked that up and did the reset. Now I have no airbag light on!!! :)

    Thanks for the help bro!
     
  11. ttocs

    ttocs Legend

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    its amazing how just a slightly loose cable can cause problems. Did you just tighten them down or did you remove/clean and then tighten them down? If you didn't clean them it sounds like there might be a slight layer of corrosion or resistance that has built up and if so you could easily gain .5v to a full volt before/after.
     
  12. mattmathis

    mattmathis Member

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    I cleaned it them too. I figured I might as well. Might save me some trouble down the road. Thanks again!!!
     
  13. ttocs

    ttocs Legend

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    good man people really just do not understand how a small/thin layer of corrosion can stop/restrict electron flow. Most people just think that its all good when metal touches. I learned all this myself as well the hard way. I didn't tighten down a battery cable enough and you could twist it 20-30 degrees. Every 2-3 months the car would not start and I would pop the hood, twist the battery cable back/forth to clean off the oxidation and then it would start. Later I went and tightened it down, but it still have a 5 degree movement but I thought that would not matter. Now it tood 5-6 months till it quit and I had to do the same.