Airbag sensor Compatibility

[Max Attitude]

Hey guys, I picked up a couple airbag sensors at the local parts yard today. Pulled them from an 03 1500 chevy. Numbers don't match my truck, sensors look the same. Did some searching on eBay and looks like they aren't compatible when I use the fitment guide. Anybody have an idea why they wouldn't work or what would be different with them? Thanks

 

[02greysixer]

I've tried every other number except the original one in my truck. I have a code for front impact. My code never went inactive. I haven't tried the correct one yet bc from what I gather only gm has it and I'm too cheap. I also have not checked my wiring either. I don't know what's different if anything.

 

[TheBac]

Hey guys, I picked up a couple airbag sensors at the local parts yard today. Pulled them from an 03 1500 chevy. Numbers don't match my truck, sensors look the same. Did some searching on eBay and looks like they aren't compatible when I use the fitment guide. Anybody have an idea why they wouldn't work or what would be different with them? Thanks

Ben will know for absolute sure, but dont our trucks have a different type of airbag system than the 1500s? Something about single stage and dual stage (I forget which one has which one)?

 

[RPM Motorsports]

Put somebody in the driver seat, have them key on then plug it in. Let us know if it's the correct sensor j/k

 

[Max Attitude]

Lol, Russ. I just talked to my GM tech buddy. He said there won't be any problem with at least trying it. Worst case scenario it will set another code. I had a feeling it will be the same as you tried 02greysixer…. FYI I put a Doorman one in my dads LBZ and it worked good. Picked it up for $100.

I'll give it a shot and report back.

 

[duratothemax]

Heavy duty truck and light duty truck/SUV have different sensors, they are NOT interchangeable.

You need a sensor for an HD truck...best to match the part number with your VIN.

Those sensors arent just a "switch" like everyone thinks they are. There is an actual microprocessor and solid state accelerometer and shock-sensor chips in there. It is a mini-computer, believe it or not.. The EFS (electronic front sensor) communicates with the SDM (airbag module, located under the drivers seat) via data...its not just a "close the wiring circuit, deploy the bags" thing like everyone assumes. The wiring going from the SDM to the EFS is databus.

Both the SDM and the EFS communicate continuously, and both units have accelerometers/force sensors in them...when an impact is detected, the SDM checks with the EFS to corroborate the impact readings/forces, and only if the two units agree that a significant-enough crash has occured, does the SDM command a bag deployment.

No harm in trying the sensor, but I doubt it will accept it. No, its obviously not just going to spontaneously deploy the bags if the wrong sensor is plugged in. But at key-on the SDM communicates with the module to ask for its serial number, calibration, and a couple other state-of-health diagnostic checks/questions.... if the sensor reports back that it is the wrong calibration for the VIN/vehicle info in the SDM, its going to fail the diagnostic and set a code.

Just buy the proper sensor for your truck/VIN. IIRC they're only $100 or so.

 

[battlegraduate09]

Ben, even though the 03 had left and right airbag sensors on the HD trucks, would one or the other be compatible in an 04+ truck that uses single middle sensors ? Just out of my personal curiosity.

 

[moparkxracer]

Anyone ever changed the sensor in the sterring collum? I swapped out my steering wheel and pulled the wires out of the sensor, I'm scared to know what the dealer wants to changed it. New steering wheel looks bad ass but not the airbag code

 

[Max Attitude]

Heavy duty truck and light duty truck/SUV have different sensors, they are NOT interchangeable.

You need a sensor for an HD truck...best to match the part number with your VIN.

Those sensors arent just a "switch" like everyone thinks they are. There is an actual microprocessor and solid state accelerometer and shock-sensor chips in there. It is a mini-computer, believe it or not.. The EFS (electronic front sensor) communicates with the SDM (airbag module, located under the drivers seat) via data...its not just a "close the wiring circuit, deploy the bags" thing like everyone assumes. The wiring going from the SDM to the EFS is databus.

Both the SDM and the EFS communicate continuously, and both units have accelerometers/force sensors in them...when an impact is detected, the SDM checks with the EFS to corroborate the impact readings/forces, and only if the two units agree that a significant-enough crash has occured, does the SDM command a bag deployment.

No harm in trying the sensor, but I doubt it will accept it. No, its obviously not just going to spontaneously deploy the bags if the wrong sensor is plugged in. But at key-on the SDM communicates with the module to ask for its serial number, calibration, and a couple other state-of-health diagnostic checks/questions.... if the sensor reports back that it is the wrong calibration for the VIN/vehicle info in the SDM, its going to fail the diagnostic and set a code.

Just buy the proper sensor for your truck/VIN. IIRC they're only $100 or so.

Yeah that's how he basically described it to me to. Thanks for posting that. I probably won't even bother trying it at this point.

He said they are set at 30mph + into a non moving object i.e.: a wall or combined speed of 2 vehicles. Pretty interesting how they work actually.

 

[duratothemax]

Ben, even though the 03 had left and right airbag sensors on the HD trucks, would one or the other be compatible in an 04+ truck that uses single middle sensors ? Just out of my personal curiosity.

Not sure? I would still like to know why the 2003's were the only HD's that have ever had two EFS's.

2001-2002 HD, single sensor, 2004-2015+ HD, single sensor. 2002 and older light duty truck/SUV had a single sensor as well.

2003 had one other oddity, but not for the silverado. All 2003 Express's had front seatbelt pretensioners, regardless of whether it was an HD or LD. Then in 2004, pretensioners went away, and didnt return until 2008 on the Expresses. Light duty and heavy duty trucks (and SUV's) both got pretensioners in 2007.5 with the GMT-900, but never had them before. Trailblazers got pretensioners in 2005 or 2006, I forget.

2014/2015+ light duty and heavy duty trucks/SUV's actually have two pretensioners per seat...one in the retractor, and one in the buckle assembly.

2003 was the year of the mid-cycle enhancement, and when the half-ton airbag systems got a complete redesign and switch to dual-stage with passenger sensing system. With the redesign to the "smart" airbag system on the half tons, they switched to two sensors on half tons, and have used two sensors on all half tons since 2003. Maybe during that one 2003 model year, they decided that even though the HD's kept the same single-stage system, they found in testing that two sensors in general were necessary for better performance, so the HD's got the two-sensor upgrade same as the light dutys. But then sometime during the 2003 model year, found out that two sensors werent really necessary on the HD's, and switched back to a single sensor on the HD's...

One of the members over on DP is one of the head engineers at GM Safety/Restraints, but unfortunately he doesnt post there anymore, otherwise Id ask him because Im curious to know the answer.

 

[duratothemax]

He said they are set at 30mph + into a non moving object i.e.: a wall or combined speed of 2 vehicles. Pretty interesting how they work actually.

Theres really no set "speed" threshold. Its all about the angle of impact, and change-of-acceleration forces. Calibrating airbag systems has got to be probably one of the most difficult jobs in the automotive industry. Not only because peoples' lives' are at stake, but also because there really is "infinity" types of crashes a vehicle can be involved in, each crash is different...and designing a computer system to be able to analyze and judge unique impacts that may have never been simulated in the lab is certainly no small feat.

In terms of restraints design, there are three components that each require equal resources, time, and effort to engineer. The seatbelts, the airbags, and the knee bolsters. Nobody ever thinks about it, but the driver side knee bolster and passenger side glove box/lower dash is actually just as critical/essential a component in crash safety as belts and airbags. The knee bolsters are actually the first components designed when engineering vehicle safety, then the belts, and finally the airbags are designed last to work properly in conjunction with the bolsters and belts.

Case in point, when GM came out with the "GM Peformance Parts" 20" wheel package for the half ton trucks/SUV's back in 2004ish, you not only get 4 wheels, but you also get a new driver side knee bolster that has one plastic rib in the back that is shaped slightly differently, and the plastic on the front part is about 1mm thicker in certain areas. Because apparently it was determined that going up to a bigger rim size altered the crash dynamics enough that a new knee bolster had to be designed before GM would put their name on the wheel package. And everyone wonders why aftermarket parts with GM's name on them are so expensive...because they actually have to meet OEM standards and regulations. A new stability-control calibration was also included with the SUV's on the 20" wheel package...which probably took quite a bit of money and man-hours to calibrate as well.

And people cant understand why vehicles are so expensive....