Airbag Diagnostic Module

Thanks for that dDUBb. My takeaway us that I need to look for shorts along all the wires that are heavy black in the diagram. Is this correct?
 
Correct .. and note the "shorting bar(s)" .. you'll want to un-plug everything and do a continuity test between the harness connector ends and ground to see if a short exists.
 
Correct .. and note the "shorting bar(s)" .. you'll want to un-plug everything and do a continuity test between the harness connector ends and ground to see if a short exists.
Please explain this in Layman's words please....
 
Unplug the wire harness connector from airbag diagnostics module and locate pin #12 ... this is connected to a few components if you follow the dark lines in the circuit.
Set your multimeter to Ohms scale and put one lead on the pin for circuit 12 and the other lead on a Known good ground.
If no short exists you should read OL ( over limit ) ..

Checking the primary sensors is where the shorting bar note comes in. You'll need to remove this fuse looking bar from the connector - it connects to pin number 2 which is grounded. Once you remove that, you can do the same with thr multimeter and check pin 17 / known good ground and pin 18 / known good ground.

Looking over this FSM diagram it doesn't correspond to the EVTM harness posted earlier in the thread. I would match the wire colors to find the correct circuits.
 
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Unplug the wire harness connector from airbag diagnostics module and locate pin #12 ... this is connected to a few components if you follow the dark lines in the circuit.
Set your multimeter to Ohms scale and put one lead on the pin for circuit 12 and the other lead on a Known good ground.
If no short exists you should read OL ( over limit ) ..

Checking the primary sensors is where the shorting bar note comes in. You'll need to remove this fuse looking bar from the connector - it connects to pin number 2 which is grounded. Once you remove that, you can do the same with thr multimeter and check pin 17 / known good ground and pin 18 / known good ground.

Looking over this FSM diagram it doesn't correspond to the EVTM harness posted earlier in the thread. I would match the wire colors to find the correct circuits.
Thanks man. I THINK I can manage this. Once again, when it stops raining I'll see what I can do!
 
OH. Big thing to remember. Do not use a power probe or meter while testing airbag circuits unless you want to blow an airbag.

Feel free to guess how I learned this.
I read this thing the first time around and just said "oh". I now have a recently acquired 95 4.6 bird that also has a code 51 and it appears that I'm going to end up knowing how to diagnose this pretty well, or at least be crippled while trying!

I don't believe you are actually saying that I can't use a regular multimeter to diagnose continuity in wires are you? I suppose in the strictest sense, a multimeter has batteries and I'm assuming that in order to determine continuity is has to send out some amount of current on the lines being tested? I guess I've never thought about this before...

So, if indeed you are saying that I can't use a regular meter without blowing the airbags, what do I need to do to prevent this before I start probing for continuity?
 
Correct .. and note the "shorting bar(s)" .. you'll want to un-plug everything and do a continuity test between the harness connector ends and ground to see if a short exists.
After looking at the diagram in detail I see a number of shorting bars. Do I need to remove more than just the one specified in the diagram with the note or do I need to remove each of them, one at a time, while I probe the related circuits?

BTW, because of my old and decrepit body, I believe it would be a good think for me to remove the passenger seat in order to avoid the most painful of back spasms trying to contort myself into that horrible space under the glove box...what do you think? ;)
 
You can use a standard multimeter provided it does not inject power into whatever circuit you are testing. Multimeters traditionally do not do this, but power probes do. Continuity tests on a multimeter also don't inject power into the circuit.

A power probe is wholly different than a multimeter. It looks like a circuit tester probe and doesn't have a dial to pick the test you want to perform.
 

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