brilliant, sensible, no nonsense, no background music, exactly what most others don't do, explain function of components so the unlearned are left with a name of a component but not necessarily how it works. brilliant video, clear speech, detailed, competent, excellent communication skills. Thank you very much
You're awesome for how concise and direct this video is. You're also awesome for sacrificing a component for everyone's education, and for editing the video down so there's no dead air :) You're awesome.
+samsical Thank you. Your learning is my learning too. I always wanted to know myself how an airbag sensor works and I didn't see any documentation out there so I made this video to share with all.
My Lexus IS 200 have experienced an airbag deployment twice in one week without me getting involved in a crash or hard impact and the indicator on the dashboard wouldn't go off. What is the problem? Help with advice please
he he "as you can see rust is probably a cause for these sensors failing" he says rigjt before removing the immaculate "plastic" sensor housing from its metal mount and then goes on to say how well sealed it is, couldent help but laugh at the contradiction. I'll tell you what causes these to fail, it's one of 3 things. 1, the resistor directly fails and the car reports a sensor problem. 2, years of warming and cooling causing expansion and contraction of solder joints breaks the circuit inside. 3, years of vibration breaks the solder joints and therefore the circuit inside. in any of these situations it will only cause a airbag fault to be reported if it affects the circuit made by the resistor, it is technically possible for the circuit to fail beyond the resistor and for the sensor to have failed while the resistor circuit is still functional and not report a fault.
007titok If the wires break then it is a wiring problem and not a sensor problem per se. If the wires don't make contact the ECU will sense an open circuit and a warning light will come on, that is the purpose of the resistor in the sensor. The sensors are quite robust and give little problems.
Thank you for this comment. The resistor can be replaced then if you have a faulty airbag sensor. You can also use a multi meter to run continuity tests to find any shorts and repair them. A resistor like this costs around three pennies. A replacement airbag sensor costs about $30-$40. Fixing a damaged solder joint costs one penny worth of solder. Clearly these are worth fixing. I wish I would've known this before placing my last time. Never again. From now on I'm fixing all my failed electronic components rather than replacing them.
@@Dalziel45 Yes they are, so you need to carefully open it and when finished carefully seal it again with some silicone caulk. Not really that hard. He shows it is easy to open in the video and he isn't even really being careful with it.
Great video! Also, the airbag computer does nothing until usually 2 or 3 sensors are tripped, so if one fails it doesnt deploy your airbags and cause an accident, this is why some airbag lights will be on for seemingly no reason, because one sensor is tripped (or not functioning at all) but none of the others are
The airbag light is on for about 6 seconds because the system does an internal check at start-up. If the airbag light is on all the time, there is something wrong in the restrain system, airbag, sensor, etc. You need to pull the fault codes from the ECU to know what is not working properly.
This may be true for your particular sensor/ system but is by no means the way they work. That is an inertia type sensor used in early systems. Ever seen airbags deploy when a vehicle is hit but sitting still? Park or drive doesn’t matter, there is no deceleration there. They utilize a potentiometer that measures strike force- impact and signal the control module to deploy the charges in the bags when enough force is detected. Pendulums in the main sensor where the first deployment methods. Now, with a vehicle running you can blow the airbags by impacting the area the area around the sensor or the sensor itself. 40 years here building wrecked cars.
Newer systems use solid state circuitry with a sensitive accelerometer in system with a microcontroller. Check out my channel for automotive electronics reverse engineering.
great video.. my question is why is that part so expensive. looks like they could make that in china for about 5 bucks. I have a 07 chev truck...price of sensor 275.00 . scam or what
+John Geise On some cars with a magnet-ball design, yes. On this type of design, most likely not, unless the sensor was physically damaged or the cam lever jammed.
HI this the best explanation in youtube. Just asking how to check the resistance between the two terminal of the side impact sensor. I mean if the sensor is bad what reading should I see , Thanks
would this help in a situation where a truck was in a collision but the bags didn't go off, maybe just the sensor went bad? or would their be hard set codes on the computer still making the light still apear?
+Handyman Helper If the bags didn't go off there is no hard code set. If the sensor was damaged and that's the error code your getting then it'll have to be replaced.
Great job on the explanation, Speedkar, you're concise and the video production was excellent. Found your video while trouble shooting my '03 Silverado, and learned way more than I could have hoped. Thanks!
Would the airbag go off if you took a sledgehammer and knocked the crap out of the sensor? I asked that because my idiot stepfather actually wants to try that.
Awesome explanation. Gave multiple diagrams of sensor variants along with not wasting time showing you spending 5 minutes to pry off glue. Please keep making videos, people need to look at yours as a standard! :)
+Daniel Faraj Thanks. Short and to the point is my style. I hate wasting time on trivial things like screws, the point of the video is to show how something works, not how to unscrew or pry something lol
I'm having an issue with the airbag/sensors on a 2006 GMC pickup, so I checked the sensors with an ohmmeter and diode checker. The resistance was very high one way (3 megohms), and infinite with the leads reversed. Measuring voltage drop, which is what a diode check does, shows there is definitely a semiconductor between the two leads of the sensor, so unfortunately not all sensors are as simple as yours. Very nice video. Well done!
Well, no. What I mean is that the airbag sensors on my vehicle, and most likely other newer vehicles, consist of more than a simple mechanical switch. Inside mine there is clearly at least one transistor / diode of some type. Your smart phone has a micro accelerometer in it for instance, which is most likely what's inside a more modern sensor. hackaday.com/2012/05/22/the-engineer-guy-explains-how-mems-accelerometer-chips-work/
@@LarryCook1960 You are right : sensors are more complicated than that.I think you have figured it out by now ; The micro accelerometer you are talking about is more likely based on piezoelectric technology that says: a crystal (be it quartz or the like) has the quality of producing electric pulse upon being impacted. So the accelerometer has a crystal quartz layer that separates two metal plates that are charged with positive and negative electrodes respectively by the crystal upon being impacted or very lightly knocked. So I think that when people measures the resistance of an airbag sensor with a multimeter , what they are measuring is the resistance of mentioned metal plates. If the piezolectric crystal that is between those metal plates , breaks for a strong external blow to the car or by simple tear-and-wear, those two metal plates would be in contact (even lightly due a tiny minor fracture of the crystal) showing an abnormal resistance or even continuity. It is even more complicated if we take into account that around the piezoelectric accelerometer there are capacitors that store some charge and a tiny transducer that converts the electric pulse generated by the cristal (upon being tested or for a legit real impact) back to the Airbag control unit (ECU) to deploy airbags if needed. That amounts to a nightmare for a newbie to test such an overcomplicated sensor device that only gets a generic message when conecting a ODBII examiner: OPEN CIRCUIT IN AIRBAG SENSOR 1 !!!! Then you start throwing parts, battery and overhauling the fucking all wire looms and connectors to the ofending fucking sensor 1. A nightmare and very entertaining PITA process!!! Good luck!!!
Well you have to remember, intellectual properties are protected by Patents. Either the manufacturer settles on using someone else's patented technology or, develops their own device which then has to undergo all the testing to certify the device. So....bottom line is I'm sure there are a dozen or more different designs, seems like people are more interested in just shooting the messenger, rather than taking the explanation for what it is worth. Like I tell my kids don't be one of the ten percent.
Great explanation! Do you know if the sensors re-set themselves after a collision or do they have to be replaced? I just finished re-building a 2013 chevy Cruze and replaced all affected parts (seat belts driver airbag and control module) but did not change the front sensors. I'm getting an error code B001A and B001B which apparently refer to pretensioner error. I checked the resistance on the seatbelt pretensioner and it is within specs. Now I'm thinking that maybe it is the front sensors that I should change. I can't find anywhere the proper resistance specs for them so can't really test. My thinking was that once the impact of the collision is over the sensor is back to its normal position and can be re used unless physically damaged from the accident of course.
+Chris Dz I've read that the sensors have to be replaced as well, though it depends on the sensor type. If its the "gold ball" type where the ball detaches itself from a magnet and gets lodged into the contacts then it might have to be replaced. If you have access to an accident free Chevy Cruze (think rental car), you can measure its sensor's resistor values and see if they matchup.
I figured it out. The front sensors are actually fine and did not need replacing after the accident. I'm guessing the magnet pulls the ball back and it's ready again. My issue turns out to be that the Chevy has two seatbelt tensioners. One is in the seatbelt assembly which I replaced. The other is attached to the seatbelt anchor and the tensioner is hidden beside/under the seat. I worked on many cars before but this is a first for me to see two separate tensioners. Just an FYI.
Even in 2015 when you uploaded that video the sensor you show is 7 to 10 years obsolete. Everything has been MEMS semiconductor devices since later 00s model years onwards.
Great video plus demonstration. But how to be so sure about the precision of this mechanism? I mean, how will it deploy only in a collision, and not in a hard braking? The borderline between a collision and a crash seems so tight...
+Matheus Bitencourt Hard braking can never have the severe deceleration forces that are experienced in a collision. Deployment is also a function of vehicle speed and other dynamics, such as steering angle, yaw, and possibly readings from the ABS sensors.
You should add that normally, three frontal sensors are used to send signals to the ECU that triggers the airbags. This type of mechanical sensor is no longer used for automotive applications, now they are all electronically based with some exceptions (venturi tubes in side impact). The ECU generally has one this mechanical sensors inside, to act as a backup system.
+wysiwyg248 Yes I agree. Of course this sensor was from the 90s when things were simple and basic. Now they use accelerometers and MEMS devices to sense impact. My cars ony have 2 frontal sensors though.
Too bad your vehicles has just two sensors, three is a much safer option. Not just from the durability viewpoint, but also with three, the ECU can make more accurate decisions relative to must fire or not fire conditions.
Well illustrated. Clearly described. Generally pretty well lit (could use better lighting when prying out the cam). Excellent editing! Really well done.
+Stephen Dee Thank you for the constructive comment! Lighting wasn't that great (filmed in basement, took many takes to get a decent shot of that cam gear).
Great information... Now if I could find the right front passenger side sensor on my 1995 MX6...I can start to find a replacement. Been lloking. Thanks for your vid...!!
@speedkar99 - great explanation, Thank You. My 2007 Ford Ranger intermittently throws a B1118-A0 Passenger Front Impact Sensor Mount/ Communication Error. There is a resistor in the sensor. I am thinking it gets out of operating resistance range after system powered up and sets the code. I am going to replace sensor first before chasing wiring problems. Thank You once again.
+Jacana Productions exactly, I would have thought it would have been a MEMS or solid-state device to detect deceleration, not just two prongs that bounce together. However rememeber this car was from the 90s...
Yes I guess and that why Toyotas are so cheap to fix vs Ze German cars. And most of the public don't or can't tell the difference any way in ride and build quality although ze germans are really building a lot worse quality vs cars from the 80s / 90s due to cost cutting.
***** The bush bar usually connects to the frame. If subject to a shock while driving off road, a vibration could be sent up to the airbag sensor on the front frame triggering the sensor.
thanks for letting me know. i have been little frustrated as nobody wants to help me. i was imagining a really nice shiny nudge bar on the front & also my brother has suggested that to me too, but i see your point. i guess it wasn't a good idea to begin with. so glad i have you helping me =] Happy Weekend my friend.!!
gardogg65 hey thanks, i usually say that to people. yes you can do anything you put your mind to. actually talking about one of his latest videos about cleaning the disc calipers, i notice when i am driving the car swerves to the left if i take my hand of the steering wheel. i was going to get that repaired & do it all myself. my car is in a double lock up garage. my car is only 4 years old, i not think i need to repair the air bag sensors just yet. i may get my brother to help me put on a nudge bar. as he was the one who suggested it to me. hmm now that he is only living few hours drive away. thanks :)
I wish I had found this video yesterday. I had the "Service Air Bag" message on my 2009 Silverado 1500. Wife needed the truck to go out of town so I didn't want her driving it without the air bag. I suspected the problem was one of the impact sensors on the Rad support but wanted to verify it before spending $100 on a new one. My Actron CP9690 scanner would not read the code even though it was advertised as doing SRS which is why I originally bought this model just in case I ever had a problem. I took it to O'Reilleys and guess what--- they couldn't read it either because they were using the Bosch version (Bosch owns Actron now) of the SAME SCANNER. I just bit the bullet and bought an impact sensor there and luckily that was the problem. After watching your video I realized all I really needed to verify it was a friggin' 1/4 watt resistor which I have drawers full of. DOH !!! Great video. Thanks.
Nice video. .... I have a doubt ... as you said rapid deceleration causes to short-circuit. How is this handled on instant braking ? If i brake my car to stop instantly does airbags get deploy?
nithukat Brakes can never get a car to stop as instantaneously as colliding with another object. The deceleration isn't as rapid and therefore the airbags won't deploy.
Noseefood that must be with very high speed.... the engagement of the senor doesn't guarantee a deployment, the computer checks for speed of the car and lots lots data before popping the bag
I think in my car (a VW) the sensor is inside the AirBag ECU itself, because there aren't Airbag sensors in any part of the vehicle (mine just have 2 front AirBags. The seatbelt pretensioners aren't electric activated in my car because it doesn't have side AirBags, they're activated mecanically by a mecanism with the disacelleration force).
Hey brother, I got a question. I watch your videos and love them. I bought a 14 model wrecked Cummins. I’m changing out the front airbags in it. I got new clockspring and airbags. Can I disconnect the battery, change them out, then reconnect the battery and drive the truck to the dealership to get them reprogrammed? You don’t think they will deploy, do you?
No it won't deploy but it also won't work with crash data in the airbag computer which is technically a risk to drive. I don't think dealerships reprogram airbag computers after collisions, they replace it or you'd have to send it out to get reflashed. I have a video on that
Is this same as an impact sensor? My car has the airbag light on all the time, and i checked with scanner, and shows that the driver's side impact sensor. My car is 2004 Gti Golf. I heard the sensor is pretty expensive.. Any idea guys?
Great Video! Thanks. I've got side sensor fault on my Renault Megane 2001 1.9dci car. How can I check the sensors? How many ohm do I have to measure on the diagnostic resistor of the sensors? Can somebody help me? Many thanks in advance...
bro u gotta way of illustrating complex processes so anybody could easily understand... thx.. btw so say an airbag deployed if u pulled those wires off tht sensor would tht stop someones car from dying...
Thanks for the feedback. Some sensors and srs computers have to be replaced (or reprogrammed) after airbag deployment. To deploy an airbag those wires not only have to touch, but it has to correlate with vehicle speed to determine deployment.
I remember a time in school where anything outside of the classes I missed out on; Airconditioning and airbags systems were left out; heck I was not allowed to take Diesel classes until the last minute; I refused
Hello! I have this problem Renault Megane ii 2008 Renault: ABS - Invalid electric power assisted steering signals Renault: Airbag/pretensioners - Computer to be replaced following impac
I get a Code 19 on my Mazda5 but had no collision. Could a very rapid deceleration as you described cause a fault. Should I replace the front crash sensor and reprogram the SAS module?
would this help in a situation where a truck was in a collision but the bags didn't go off, maybe just the sensor went bad? or would their be hard set codes on the computer still making the light still apear?
would this help in a situation where a truck was in a collision but the bags didn't go off, maybe just the sensor went bad? or would their be hard set codes on the computer still making the light still apear?
سلام سپاس ودرود وبسیار تشکر مهندس عزیز از اطلاعات فنی عالی شما ممنونم درصورت امکان بهر طریق ممکن دوبله بفارسی ویا ترجمه زیر نویس بفرمایید حیف است این اطلاعات بسیار مفید شما را فقط بیک زبان داشته باشیم .خواهشمندم جدا روی این موضوع اندیشه و ضرورتا اقدام ونتیجه را ابلاغ نمایید..بی نهایت تشکر....👍....👍 و.....هزاران 👍.... ارزوی من سلامتی وشادی شماست از خدای مهربان...
My question would be,,,,once there is a crash and the entire airbag system has performed correctly are these sensors no longer functional after the repairs have been done and the crash data scrubbed from the computer ? all be it , i am sure it would throw a code during the resetting of the system if it were bad, but can they be trusted ? and are the a one time use sensor ?
this is the best "how it works" video ive seen in TH-cam... 0 second wasted.
+723lion thanks, short and to the point is how it should be
totaly agree!
723lion yes
yes
u so right
Huh.... Way simpler than i would have thought.
Yes very simple, though there are more complex airbag sensors in newer cars.
Varies between vehicle
Also the computer has to see many other signals before deploying bag like seat position, speed vehicle is traveling
And it cost only 90$
A very good explanation of the theory of operation, followed a detailed illustrative visual component. Good job.
+George Rivera Thank you
speedkar99 I bought a car from an auction with the driver and passenger airbag deployed. Do I just replace the airbags and reset the module?
Mart25F Nope. You have to replace all the crash sensors, SRS computer, aka SRS deployment module all the air bags and the initiator module.
brilliant, sensible, no nonsense, no background music, exactly what most others don't do, explain function of components so the unlearned are left with a name of a component but not necessarily how it works. brilliant video, clear speech, detailed, competent, excellent communication skills. Thank you very much
Thanks. Short and to the point is my style
You're awesome for how concise and direct this video is. You're also awesome for sacrificing a component for everyone's education, and for editing the video down so there's no dead air :)
You're awesome.
+samsical Thank you. Your learning is my learning too. I always wanted to know myself how an airbag sensor works and I didn't see any documentation out there so I made this video to share with all.
If anyone wondering that's a 1M Ohm resister
do you happen to know, if i could use a resistor insted of an impact sensor? Thanks fam :D
Yours is a gold standard 'how it works ' video. Zero time wasted. Please continue your good work so that we can all benefit from it.
I cringed a little when speedkar ran a blade on the plastic housing with his finger underneath and it slipped a little
My Lexus IS 200 have experienced an airbag deployment twice in one week without me getting involved in a crash or hard impact and the indicator on the dashboard wouldn't go off. What is the problem? Help with advice please
1:48 How will rust affect the interior parts due to rust if they are sealed, as you indicated later in the video
missed your thumb at 2.12
he he "as you can see rust is probably a cause for these sensors failing" he says rigjt before removing the immaculate "plastic" sensor housing from its metal mount and then goes on to say how well sealed it is, couldent help but laugh at the contradiction.
I'll tell you what causes these to fail, it's one of 3 things.
1, the resistor directly fails and the car reports a sensor problem.
2, years of warming and cooling causing expansion and contraction of solder joints breaks the circuit inside.
3, years of vibration breaks the solder joints and therefore the circuit inside.
in any of these situations it will only cause a airbag fault to be reported if it affects the circuit made by the resistor, it is technically possible for the circuit to fail beyond the resistor and for the sensor to have failed while the resistor circuit is still functional and not report a fault.
If the cables in the connector outside that seal rust, they can break, making the sensor effectively broken
007titok
If the wires break then it is a wiring problem and not a sensor problem per se. If the wires don't make contact the ECU will sense an open circuit and a warning light will come on, that is the purpose of the resistor in the sensor. The sensors are quite robust and give little problems.
Thank you for this comment. The resistor can be replaced then if you have a faulty airbag sensor. You can also use a multi meter to run continuity tests to find any shorts and repair them. A resistor like this costs around three pennies. A replacement airbag sensor costs about $30-$40. Fixing a damaged solder joint costs one penny worth of solder. Clearly these are worth fixing. I wish I would've known this before placing my last time. Never again. From now on I'm fixing all my failed electronic components rather than replacing them.
@@artbyrobot1 But aren't the solder joints, you know...…... inside...?
@@Dalziel45 Yes they are, so you need to carefully open it and when finished carefully seal it again with some silicone caulk. Not really that hard. He shows it is easy to open in the video and he isn't even really being careful with it.
what's the ohm resistance of a good sensor?
I don't recall but you can grab it off those resistor color bands
"you need to update srs computer to windows 10. Please restart your airbags."
Great video! Also, the airbag computer does nothing until usually 2 or 3 sensors are tripped, so if one fails it doesnt deploy your airbags and cause an accident, this is why some airbag lights will be on for seemingly no reason, because one sensor is tripped (or not functioning at all) but none of the others are
+007K Yes, correct. It also has to do with vehicle speed and yaw.
The airbag light is on for about 6 seconds because the system does an internal check at start-up. If the airbag light is on all the time, there is something wrong in the restrain system, airbag, sensor, etc. You need to pull the fault codes from the ECU to know what is not working properly.
+wysiwyg248 Yes that's exactly how it works.
+speedkar99 - I agree with " Speed & Yaw ". There are many times I have hit the Front Bumper and the Air Bags NEVER deployed!
Thanks for the video.
Be careful when using a cutter.
You got me scared !
Lol
Yea safety first!
Reminded me of when I first sliced my finger open when I was ten using a razor blade.
This may be true for your particular sensor/ system but is by no means the way they work. That is an inertia type sensor used in early systems. Ever seen airbags deploy when a vehicle is hit but sitting still? Park or drive doesn’t matter, there is no deceleration there. They utilize a potentiometer that measures strike force- impact and signal the control module to deploy the charges in the bags when enough force is detected. Pendulums in the main sensor where the first deployment methods. Now, with a vehicle running you can blow the airbags by impacting the area the area around the sensor or the sensor itself. 40 years here building wrecked cars.
You have explained so well!! I get it now!!!
+Angelina Chow Thanks
Superb , thanks for the video
Thanks
Newer systems use solid state circuitry with a sensitive accelerometer in system with a microcontroller. Check out my channel for automotive electronics reverse engineering.
True, newer systems use MEMs devices to detect deceleration. Nice channel you got there.
I wonder how many OHMs is the diagnostic resistor?
Looks like a simple design, besides designing that computer and chip.
very clear explanation for accecalaration of sensors and activity
+Tamilmaran C thanks
great video.. my question is why is that part so expensive. looks like they could make that in china for about 5 bucks. I have a 07 chev truck...price of sensor 275.00 . scam or what
$5 sensors aren't made the same as the OE.
clear and concise, much appreciated but please use caution with that knife
+Melvin Collins agreed. Thanks
does that need to be replaced after the airbags go off?
+John Geise On some cars with a magnet-ball design, yes. On this type of design, most likely not, unless the sensor was physically damaged or the cam lever jammed.
+speedkar99. thx man
No, but the rest of the car does :D
HI this the best explanation in youtube. Just asking how to check the resistance between the two terminal of the side impact sensor. I mean if the sensor is bad what reading should I see , Thanks
What ever resistance is the color band of the resistor ...each sensor is different
would this help in a situation where a truck was in a collision but the bags didn't go off, maybe just the sensor went bad? or would their be hard set codes on the computer still making the light still apear?
+Handyman Helper If the bags didn't go off there is no hard code set. If the sensor was damaged and that's the error code your getting then it'll have to be replaced.
nice,,,talker,,no bullshit,,stories about your life....nice,,wish you be in every video of youtube...
Thanks
No BS is my style
Would slamming on the brakes really hard and suddenly not also trigger the airbag? That ball will leave the magnet if I slam on the brakes abruptly.
Slamming the brakes is nothing compared to the force of a crash
Great job on the explanation, Speedkar, you're concise and the video production was excellent. Found your video while trouble shooting my '03 Silverado, and learned way more than I could have hoped. Thanks!
+Jesse Crips-Sorger Glad you learned from it. Thanks for the feedback.
Would the airbag go off if you took a sledgehammer and knocked the crap out of the sensor? I asked that because my idiot stepfather actually wants to try that.
I would actually like to see that work ...
I'm sure the car takes readings such as speed and engine RPM
Awesome explanation. Gave multiple diagrams of sensor variants along with not wasting time showing you spending 5 minutes to pry off glue. Please keep making videos, people need to look at yours as a standard! :)
+Daniel Faraj Thanks. Short and to the point is my style. I hate wasting time on trivial things like screws, the point of the video is to show how something works, not how to unscrew or pry something lol
I have a question for a gear head with newer models! Please help me, I need to know if I’m going to get screwed over!
Yes
I'm having an issue with the airbag/sensors on a 2006 GMC pickup, so I checked the sensors with an ohmmeter and diode checker. The resistance was very high one way (3 megohms), and infinite with the leads reversed. Measuring voltage drop, which is what a diode check does, shows there is definitely a semiconductor between the two leads of the sensor, so unfortunately not all sensors are as simple as yours. Very nice video. Well done!
That's true, a diode could also be used as a check device as well
Well, no. What I mean is that the airbag sensors on my vehicle, and most likely other newer vehicles, consist of more than a simple mechanical switch. Inside mine there is clearly at least one transistor / diode of some type. Your smart phone has a micro accelerometer in it for instance, which is most likely what's inside a more modern sensor. hackaday.com/2012/05/22/the-engineer-guy-explains-how-mems-accelerometer-chips-work/
@@LarryCook1960 You are right : sensors are more complicated than that.I think you have figured it out by now ; The micro accelerometer you are talking about is more likely based on piezoelectric technology that says: a crystal (be it quartz or the like) has the quality of producing electric pulse upon being impacted. So the accelerometer has a crystal quartz layer that separates two metal plates that are charged with positive and negative electrodes respectively by the crystal upon being impacted or very lightly knocked. So I think that when people measures the resistance of an airbag sensor with a multimeter , what they are measuring is the resistance of mentioned metal plates. If the piezolectric crystal that is between those metal plates , breaks for a strong external blow to the car or by simple tear-and-wear, those two metal plates would be in contact (even lightly due a tiny minor fracture of the crystal) showing an abnormal resistance or even continuity. It is even more complicated if we take into account that around the piezoelectric accelerometer there are capacitors that store some charge and a tiny transducer that converts the electric pulse generated by the cristal (upon being tested or for a legit real impact) back to the Airbag control unit (ECU) to deploy airbags if needed. That amounts to a nightmare for a newbie to test such an overcomplicated sensor device that only gets a generic message when conecting a ODBII examiner: OPEN CIRCUIT IN AIRBAG SENSOR 1 !!!! Then you start throwing parts, battery and overhauling the fucking all wire looms and connectors to the ofending fucking sensor 1. A nightmare and very entertaining PITA process!!! Good luck!!!
Well you have to remember, intellectual properties are protected by Patents. Either the manufacturer settles on using someone else's patented technology or, develops their own device which then has to undergo all the testing to certify the device. So....bottom line is I'm sure there are a dozen or more different designs, seems like people are more interested in just shooting the messenger, rather than taking the explanation for what it is worth. Like I tell my kids don't be one of the ten percent.
This presentation is the perfect illustration for the famous Arabic proverb (Brevity is clarity)
our lives are depending on two copper contacts.
What about oxidation ?
+King Parodije Its closed within the plastic cube
Great explanation! Do you know if the sensors re-set themselves after a collision or do they have to be replaced? I just finished re-building a 2013 chevy Cruze and replaced all affected parts (seat belts driver airbag and control module) but did not change the front sensors. I'm getting an error code B001A and B001B which apparently refer to pretensioner error. I checked the resistance on the seatbelt pretensioner and it is within specs. Now I'm thinking that maybe it is the front sensors that I should change. I can't find anywhere the proper resistance specs for them so can't really test. My thinking was that once the impact of the collision is over the sensor is back to its normal position and can be re used unless physically damaged from the accident of course.
+Chris Dz I've read that the sensors have to be replaced as well, though it depends on the sensor type. If its the "gold ball" type where the ball detaches itself from a magnet and gets lodged into the contacts then it might have to be replaced.
If you have access to an accident free Chevy Cruze (think rental car), you can measure its sensor's resistor values and see if they matchup.
I figured it out. The front sensors are actually fine and did not need replacing after the accident. I'm guessing the magnet pulls the ball back and it's ready again. My issue turns out to be that the Chevy has two seatbelt tensioners. One is in the seatbelt assembly which I replaced. The other is attached to the seatbelt anchor and the tensioner is hidden beside/under the seat. I worked on many cars before but this is a first for me to see two separate tensioners. Just an FYI.
2005 Camry with DTC 1901 open squib. What are the common fixes? Seatbelt buckle assy and/or seat belt assy?
+DIY-HAVEN means there's a loose connection...check under the seat
speedkar99 car was in an accident. Already replaced the airbag and Left front airbag sensor. I didn't see loose connections under the seat
unfortunately srs computer stopped working please restart
+Stone Heart please see my air bag computer reset video
blue screen of death
@@speedkar99 can the crash/impact sensor be reused after it has deployed an airbag?
100% excellent, this is the gold standard for how these videos should be! Thanks!!
Exactly, short and to the point.
that's an old school impact sensor, newer sensors don't look anything like it
Yeah it's old
Awesome I never understood how it worked.
It has to be an electronic accelerometer in newer cars, right? I don't see this in a modern vehicle...
+Ri Max yes, or some have a gold ball that works with inertia
how old is that car for that much corrosion to be on the sensor contact? Or is car parked near to a lake or ocean?
It's Canada. We use salt in the Winter that accerates corrosion
That doesn't look like a very good sensor.
Seems kinda flimsy to rely your life on eh
Even in 2015 when you uploaded that video the sensor you show is 7 to 10 years obsolete. Everything has been MEMS semiconductor devices since later 00s model years onwards.
That's a highest grade tutorial on the market.
Thanks for the compliment
my sensor only has 1 wire.. was wondering how it works with just one wire
Ground
2:12 was quite scary...
Спасибо. Давно интересовала эта тема. Очень интересный рассказ с теорией и наглядной демонстрацией устройства датчика.
Great video plus demonstration. But how to be so sure about the precision of this mechanism? I mean, how will it deploy only in a collision, and not in a hard braking? The borderline between a collision and a crash seems so tight...
+Matheus Bitencourt Hard braking can never have the severe deceleration forces that are experienced in a collision. Deployment is also a function of vehicle speed and other dynamics, such as steering angle, yaw, and possibly readings from the ABS sensors.
Very interesting video ,thank you very much.
You are welcome
Straight to the point, crystal clear explanation. Thank you!
what triggers the airbag itself ?
shortage, voltage, or encoded signal ?
+King Parodije shortage of the resistor by the two contacts from intertia
Hi. How can we know if the impact sensor is busted? What is the status in multimeter between damage and active sensor?
Test resistance with multimeter
@@speedkar99 what shld be the measurement of resistance? I got 0.8ohm
"Now im just going to grind these spot welds"
Love from India bro what are the names of these inside sensor
The newer sensors use MEMS devices to sense deceleration
You should add that normally, three frontal sensors are used to send signals to the ECU that triggers the airbags. This type of mechanical sensor is no longer used for automotive applications, now they are all electronically based with some exceptions (venturi tubes in side impact). The ECU generally has one this mechanical sensors inside, to act as a backup system.
+wysiwyg248 Yes I agree. Of course this sensor was from the 90s when things were simple and basic. Now they use accelerometers and MEMS devices to sense impact.
My cars ony have 2 frontal sensors though.
Too bad your vehicles has just two sensors, three is a much safer option. Not just from the durability viewpoint, but also with three, the ECU can make more accurate decisions relative to must fire or not fire conditions.
Are you Garth from Waynes world?
No
HI, CAN I PUT A SENSOR FROM A DIFFERENT CAR MANUFACTURER
+Mohammed Hammad Probably not. Resistances have to match.
Well illustrated. Clearly described. Generally pretty well lit (could use better lighting when prying out the cam). Excellent editing! Really well done.
+Stephen Dee Thank you for the constructive comment! Lighting wasn't that great (filmed in basement, took many takes to get a decent shot of that cam gear).
That means we can install aftermarket airbags
How?
Great information... Now if I could find the right front passenger side sensor on my 1995 MX6...I can start to find a replacement. Been lloking.
Thanks for your vid...!!
Super cool man, thank you!!
No problem!
@speedkar99 - great explanation, Thank You. My 2007 Ford Ranger intermittently throws a B1118-A0 Passenger Front Impact Sensor Mount/ Communication Error. There is a resistor in the sensor. I am thinking it gets out of operating resistance range after system powered up and sets the code. I am going to replace sensor first before chasing wiring problems. Thank You once again.
GREAT JOB on the Video as ALWAYS !!! A+++++++++++++++++++++++++
+Jordan Bronson thanks
low tech would of thought this would be solid state ?
+Jacana Productions exactly, I would have thought it would have been a MEMS or solid-state device to detect deceleration, not just two prongs that bounce together. However rememeber this car was from the 90s...
Yes I guess and that why Toyotas are so cheap to fix vs Ze German cars. And most of the public don't or can't tell the difference any way in ride and build quality although ze germans are really building a lot worse quality vs cars from the 80s / 90s due to cost cutting.
i am wanting to put a nudge bar on my Toyota Rukus but nobody can help me. think it has a lot to do with the air bag sensor. what do you think.?
***** The bush bar usually connects to the frame. If subject to a shock while driving off road, a vibration could be sent up to the airbag sensor on the front frame triggering the sensor.
thanks for letting me know. i have been little frustrated as nobody wants to help me. i was imagining a really nice shiny nudge bar on the front & also my brother has suggested that to me too, but i see your point. i guess it wasn't a good idea to begin with. so glad i have you helping me =] Happy Weekend my friend.!!
Thanks
your'e welcome. i have had too many knock backs to realize my much wanted nudge bar was only just a dream ;)
gardogg65 hey thanks, i usually say that to people. yes you can do anything you put your mind to. actually talking about one of his latest videos about cleaning the disc calipers, i notice when i am driving the car swerves to the left if i take my hand of the steering wheel. i was going to get that repaired & do it all myself. my car is in a double lock up garage. my car is only 4 years old, i not think i need to repair the air bag sensors just yet. i may get my brother to help me put on a nudge bar. as he was the one who suggested it to me. hmm now that he is only living few hours drive away. thanks :)
Awesome video. I was trying to make out the resistance. Is it a black brow brow ring?
Anyway you can check and let us know 😊
I wish I had found this video yesterday. I had the "Service Air Bag" message on my 2009 Silverado 1500. Wife needed the truck to go out of town so I didn't want her driving it without the air bag. I suspected the problem was one of the impact sensors on the Rad support but wanted to verify it before spending $100 on a new one. My Actron CP9690 scanner would not read the code even though it was advertised as doing SRS which is why I originally bought this model just in case I ever had a problem. I took it to O'Reilleys and guess what--- they couldn't read it either because they were using the Bosch version (Bosch owns Actron now) of the SAME SCANNER. I just bit the bullet and bought an impact sensor there and luckily that was the problem. After watching your video I realized all I really needed to verify it was a friggin' 1/4 watt resistor which I have drawers full of. DOH !!! Great video. Thanks.
Glad it helped
Dude don't u need that in case of an emergency situation
+Zexify Gaming Why not?
Also do Turn Signal Flasher.
Good idea bud!
Nice video. .... I have a doubt ...
as you said rapid deceleration causes to short-circuit. How is this handled on instant braking ? If i brake my car to stop instantly does airbags get deploy?
nithukat Brakes can never get a car to stop as instantaneously as colliding with another object. The deceleration isn't as rapid and therefore the airbags won't deploy.
speedkar99 thank you for the information
that switch seems to be too low tech to be reliable.
+Noseefood yea I was a bit surprised how simple it was when I opened it.
speedkar99 as long as it works... i've heard side airbags deploying when u hit the curve hard.
Noseefood that must be with very high speed.... the engagement of the senor doesn't guarantee a deployment, the computer checks for speed of the car and lots lots data before popping the bag
Agree I’m shocked
For something this simplistic, why in the hell does it cost $592.99 for part number SU15891 which is for a 2002 Chevrolet Silverado?
All srs components are expensive
Pry those what?, over
I think in my car (a VW) the sensor is inside the AirBag ECU itself, because there aren't Airbag sensors in any part of the vehicle (mine just have 2 front AirBags. The seatbelt pretensioners aren't electric activated in my car because it doesn't have side AirBags, they're activated mecanically by a mecanism with the disacelleration force).
Cool, yes every car is different...see my seat belt video for more on that
Hey brother, I got a question. I watch your videos and love them. I bought a 14 model wrecked Cummins. I’m changing out the front airbags in it. I got new clockspring and airbags. Can I disconnect the battery, change them out, then reconnect the battery and drive the truck to the dealership to get them reprogrammed? You don’t think they will deploy, do you?
No it won't deploy but it also won't work with crash data in the airbag computer which is technically a risk to drive.
I don't think dealerships reprogram airbag computers after collisions, they replace it or you'd have to send it out to get reflashed. I have a video on that
Is this same as an impact sensor? My car has the airbag light on all the time, and i checked with scanner, and shows that the driver's side impact sensor.
My car is 2004 Gti Golf. I heard the sensor is pretty expensive.. Any idea guys?
Perhaps the diagnostics manual can hint how to test the sensor with a multimeter to verify if it's the sensor, wiring or computer
Insane to think, the only thing preventing an explosive blasting not even a meter away from my face is a piece of metal not being hit hard enough
So can hard braking potentially trigger them?
+TheMidnightNarwhal braking hard can't generate the force to trigger these.
Great Video! Thanks. I've got side sensor fault on my Renault Megane 2001 1.9dci car. How can I check the sensors? How many ohm do I have to measure on the diagnostic resistor of the sensors? Can somebody help me? Many thanks in advance...
+Kotiti You might want to check the repair manual for the resistor values.
bro u gotta way of illustrating complex processes so anybody could easily understand... thx.. btw so say an airbag deployed if u pulled those wires off tht sensor would tht stop someones car from dying...
Thanks for the feedback. Some sensors and srs computers have to be replaced (or reprogrammed) after airbag deployment. To deploy an airbag those wires not only have to touch, but it has to correlate with vehicle speed to determine deployment.
How many Ohms should my Jeep impact sensor read?? Mine currently reads 500kohms? Is this too high or too low?
Very nice! You were to the point and showed how these sensors work using a diagram then actually taking one apart. Good teaching, and thank you.
You're welcome!
I remember a time in school where anything outside of the classes I missed out on; Airconditioning and airbags systems were left out; heck I was not allowed to take Diesel classes until the last minute; I refused
Hello! I have this problem Renault Megane ii 2008
Renault: ABS - Invalid electric power assisted steering signals
Renault: Airbag/pretensioners - Computer to be replaced following impac
+Silva Talia Yes you will have to replace the sensors, pretensioner and computer following a crash. The computer can be hacked and reset though.
I get a Code 19 on my Mazda5 but had no collision. Could a very rapid deceleration as you described cause a fault. Should I replace the front crash sensor and reprogram the SAS module?
+Matt Keefe first try reset and check wiring
I recently got into a accident, the car flipped and none of the airbags opened. It's a 2016 Mitsubishi pajero
+Mohammed Abubaker sorry to hear
You know a Formula 1 car. When they brake hard would that deceleration be enough to trigger normal car airbag sensors?
would this help in a situation where a truck was in a collision but the bags didn't go off, maybe just the sensor went bad? or would their be hard set codes on the computer still making the light still apear?
would this help in a situation where a truck was in a collision but the bags didn't go off, maybe just the sensor went bad? or would their be hard set codes on the computer still making the light still apear?
سلام سپاس ودرود وبسیار تشکر مهندس عزیز از اطلاعات فنی عالی شما ممنونم
درصورت امکان بهر طریق ممکن دوبله بفارسی ویا ترجمه زیر نویس بفرمایید
حیف است این اطلاعات بسیار مفید شما را
فقط بیک زبان داشته باشیم .خواهشمندم
جدا روی این موضوع اندیشه و ضرورتا اقدام ونتیجه را ابلاغ نمایید..بی نهایت تشکر....👍....👍 و.....هزاران 👍....
ارزوی من سلامتی وشادی شماست از خدای مهربان...
@speedkar99 does front bumper affect the opening of airbag,or does it affect the sensor in any way ??
How many of these are in a car?
+Хозе Гонзалез 2 in front
More if you have side airbags
NICE EDITING!! Most people make u watch unnecessary long videos that make u just skip the video to a more INTERESTING SHOW THX FOR UPLOADING!!
+juan aranda Thanks, I like making videos short and to the point so it's not boring to watch and you get the information you want right away.
So cheap junky switch
I too was surprised
Nice Job
My question would be,,,,once there is a crash and the entire airbag system has performed correctly are these sensors no longer functional after the repairs have been done and the crash data scrubbed from the computer ? all be it , i am sure it would throw a code during the resetting of the system if it were bad, but can they be trusted ? and are the a one time use sensor ?
+ron slaughter These aren't one time use, but some are, provided they're not damaged
it's so fcking mechanical! Can't believe our lives depend on things like these during a collision.
+Aravind Nair Newer cars use MEMs sensors or accelerometers