SRS/Airbag diagnostics and diagnostic tools

Thomas Technician Manassas Park, Virginia Posted   Latest  
Discussion
Safety
2009 Pontiac G6 2.4L (B) 4-spd (4T45-E)

Good morning every one. This is my first post on Diagnostic Network and I'm hoping to learn from you all on a topic that I've thinking about lately. The topic I'm hoping to get information or advise on is SRS/Airbag diagnostics with the use of a "load substitute" tool or the use of varying resistances. I'm still a young tech and have been taught that when diagnosing Airbag faults you should use a ohm meter. While i still think it is a tool to use in airbag faults over the years i have developed an attitude of that is to much work and is not good enough for me. I have heard of people using varying resistances to put in place of an air bag to verify if its a wiring or module issue or airbag/ component itself with the help of a scan tool. I like this idea and am hesitant on using it due to not wanting to make things deploy manly because I do not fully know "X" component should have "X" resistance. So i'm asking for knowledge from you all out there that use a load substitute what exactly do you use, is there a tool i can buy or something you can build? Also what safety needs to be taken into account when using a substitute? 

I have a 2009 G6 with airbag light on and airbag system fault message. Fault code B0013 Driver steering airbag deploymnet loop stage 2 resistance above threshold. When one looks uo GM SI for this fault, circuit/system testing indicates the use of load tool adapters. 

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David Technical Support Specialist
Ann Arbor, Michigan
David
 

Welcome Thomas, You are thinking correctly about the use of an ohm meter with an airbag still plugged into the circuit. DO NOT do it. An ohm meter uses a battery, which could send power down the circuit and deploy the airbag. Most of the OEM's do have special adapters that have the correct resistance to plug into the specific airbag connector to "take the place" of the actual airbag for

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Sean Owner
Cornville, Arizona
Sean
 

I have looked into this in the past, and have found companies selling fixed resistance value tools for generic applications, the oe tools, which in Ford's case can get quite costly, or the variable resistance type. Currently I am thinking about getting the Kent Moore J-36884-A, because it can be adapted to be a universal one, and it goes from 1-14 ohms. If you search ebay for airbag tester, you

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Don Owner
Richardson, Texas
Don
 

Thomas, If you can find a resistor with 2-3 Ohms of resistance that will work just fine, and if I remember correctly several of the park lamp and break lamp bulbs have the correct resistance and you can run some wires from it to simulate. Another way is to short the wires together as see if the code changes to a below threshold. As stated if using the resistor ensure on there is not a shorting

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Thomas Technician
Manassas Park, Virginia
Thomas
 

Hey Don thanks for the reply. So believe I know what the shorting bars are. When I disconnected the connector from the steering wheel coil I saw that the 4 female pins had what I’d describe as metal tabs hat had tension to them. Please correct me if I’m mistaken. i wanna make sure I understand if I unplug the air bag and the shorting bar is say in the clock spring then I CAN NOT use the

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Don Owner
Richardson, Texas
Don
 

Correct the metal tabs with tension are the shorting bars. You can use the resistance in any situation but You must raise the tension on the bars. Toothpicks work well to place Between the terminal and the bar. Also look for code change If the shorting bar is on the connector when it is unpluggeg. Stages are for the force need in the deployment. The vehicle monitors several factors some

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Martin Instructor
Burnaby, British Columbia
Martin
 

Hi Thomas. Please discontinue Ohming SIR/Airbag system circuits unless directed to do so, for your own safety, as has been mentioned elsewhere. When a deployment loop excessive resistance DTC sets, the scan tool will display the resistance of the related loop. As also mentioned, we utilize tool with the appropriate adapters of which there are many. Yes, you can use a resistor to substitute a

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Thomas Technician
Manassas Park, Virginia
Thomas
 

Thanks for the reply Martin. Unfortunately the Tech 2 did not offer but 4 pids in the SIR module data. Battery voltage, airbag request lamp on or off and 2 others that did not lend a hand in resistances. Thanks for your time and information.

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Mike Mobile Technician
Mount Pleasant, South Carolina
Mike
 

This kit from AESWave has a special adapter that can be used to check airbag circuits. Essentially you can just use resistors that you could purchase from Radio Shack (if they were still open) but this kit has many other uses as well so if you were considering purchasing a tool dedicated to airbags I think you will find this kit has plenty of other uses and you'll end up using it more and more

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Thomas Technician
Manassas Park, Virginia
Thomas
 

Mike thanks for your time and knowledge it is greatly appreciated. I have my own story with an airbag module actually, however i was luck enough not to have deployed anything. I had a Mercedes Benz 204, C class. the passenger seat had been moved to the maximum position forward it would go, the cable had broke off under the frame and motor was striped so i could not get the the two front bolts

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Mike Mobile Technician
Mount Pleasant, South Carolina
Mike
 

Glad nothing blew. I've heard stories of the impact sensors getting hit and deploying bags as well but I think that's pretty hard to do and/or might be a myth. You can't learn and grow as a technician without running into things like that. I used to beat myself up over those things. At the end of the day half of the services we do require a battery disconnect which now involves 20 minutes of

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Mike Mobile Technician
Mount Pleasant, South Carolina
Mike
 

So I was wrong I've been using a 2 ohm resistor. This is what I had mentioned from AESWave kit. Inside of the cap there is a little resistor. These are interchangeable and a few come in the kit. Here is a sample diag on a Chrysler 200 using that kit. Vehicle had a code for the deployment loop in the seat. Here is the wiring diagram identifying that circuit. All I had to do was install that

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Thomas Technician
Manassas Park, Virginia
Thomas
 

Mike really like the photos thank you! I'm more of a "show me and let me practice" type. I'm sold on that aeswave kit. I've been eyeing that kit, the relay jumper/measurement tool and the DLC BOB.

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Rudy Technician
Montebello, California
Rudy
 

I use a variable resitor that I got in an automotive electrical test lead kit, its very accurate(as measured by my fluke) I cant remember a time when more than 2.3-2.5 ohms was needed.

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Thomas Technician
Manassas Park, Virginia
Thomas
 

How do you dial in the resistance?

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Rudy Technician
Montebello, California
Rudy
 

Didnt realize the picture was blurry. The black portion around the gauge turns. Right now it is set at 2 ohms.

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Bob Diagnostician
East Longmeadow, Massachusetts
Bob
 

I have that same kit and it makes testing stupid easy. For instance, say you have a code for driver side squib open. Remove airbag from steering wheel and insert the resistor. Code gone? Airbag is bad. Or, lets say the Code is still present? Step 2 would be to unplug the harness on the opposite side of the clockspring and insert resistor. Code now gone? Bad Clockspring. Pretty simple, with one

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Thomas Technician
Manassas Park, Virginia
Thomas
 

Bob I have heard great things about sibilant 22 but i have never used it. I will have to buy some to try.

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