Airbag reinstall
Thread Starter
Intermediate
Joined: Nov 2011
Posts: 29
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Airbag reinstall
Hey guys, '93 manual coupe. i recently got into a minor wreck, and it was mostly just body damage but airbags deployed. and i got another parts car for it and i was wondering if y'all know how to take out the airbag and if ill need to reset anything and how so it doesn't deploy again when i reconnect it. or if yall can help me through the rebuild step by step i'd be much appreciated! if you guys would like pictures of it i can provide some.
Instructor
Joined: Apr 2013
Posts: 144
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From: NW Arkansas - usually winter in FL
I was a vehicle crash engineer for a few years and have replaced a few of these and it is not rocket science. It has been a few decades so I will attempt to make this as generic as practical. Not sure if this applies to your car or not but here goes - LOL.
First thing - get a factory service manual and follow the instruction therein. You are going to find the FSM very useful in repairing other crash areas so might as well spend the bucks and spring for one.
Very important: Disconnect the battery and wait about a minute prior to doing any work on anything. The air bag control module - ABCM - has charged capacitors which will supply current to deploy the air bags even if the battery is the first thing destroyed in a crash sequence. So even without battery power, the air bag system will still function normally for a couple of seconds during a crash environment. Generally the capacitors will discharge in just a few seconds but it is best to be safe and wait one minute before doing any work.
My knowledge is old school and I certainly am not an expert on your specific vehicle but we used two sensors to control deployment of the air bags. One is a "G-sensor" located inside the airbag control module itself and the other is called a "safeing-sensor" and it is located near the front if the car. Both sensors must activate simultaneously prior to the air bags being deployed. We didn't want some jerk to be able to deploy the airbag with a sledge hammer pounding on the front bumper area. Usually there are two safeing-sensors, one at each front corner of the vehicle. The Air Bag Control Module itself is usually located in the vehicle in an area which is not commonly damaged in a crash. We located the ABCM on the tunnel just behind the shifter. I have no idea where yours is located. Consult the FSM.
The safeing-sensors up front are almost always destroyed in a crash so most likely, you will have to replace them. If the Air Bag Control Module is not damaged, you will probably be ok to use it again.
Using the FSM, be absolutely positive there are no wires which have been damaged as a result of the crash. With the battery still disconnected, install the replacement parts as required. Tighten all fasteners securely - do not let the sensors or module just dangle from the wires. Secure everything - period. The electrical connectors to the various sensors are gold plated to insure excellent reliability over an extended time frame so do not use substitutes. If a connector appears to have been damaged, replace it with the gold plated parts.
What we used to do as the final step was to position the ignition switch to the run position and then connect the vehicle battery as the last event. If the system is defective and the air bag deploys, then it is best that you are outside the vehicle.
Some other folks used to install everything except the airbags themselves and then using a scan tool, check things for codes. There will be an airbag disconnect/continuity code for sure but by using the scan tool it was possible to safely ferret out any other problems without the danger of an airbag deployment. If there are no codes other than the airbag continuity ones, then you can once again disconnect the battery and after waiting a minute or two, install the air bags. Some guys used to leave the ignition key off and after connecting the battery, rotate the ignition key while remaining as low as possible in the passenger seat. That always scared me - it was beyond my "chicken limit" so I did it all from outside the car.
The airbag system does its obligatory system check when the key is cycled to the on position and there should be a bulb check light for a few seconds. If there is no warning lamp illuminated after the bulb check, then you are good to go. The airbag diagnostics are quite complicated and are very reliable - undoubtedly the most reliable feature on the car - well, guess that ABS brakes rank right up there too. If the lamp comes on as it should for the bulb check during the initial key on episode and then goes out, everything is ok. If the bulb check doesn't work or if the lamp stays illuminated, then something is wrong and my advice is do not drive the vehicle until the system has been repaired.
Undoubtedly your car has airbag dust all over the place. Airbags are pyrotechnic and use sodium azide as the explosive charge to generate the gases required to inflate the airbag. By itself, sodium azide is quite nasty stuff but when the bag deploys, the sodium azide reacts with moisture in the atmosphere and within milliseconds it becomes inert. But having said that, my advice is to not inhale anymore of the stuff than you have to. Use a mask and goggles and gloves when vacuuming the residue out.
Like eluded to prior, this information is dated. There was investigation into combining the sensors into a single module and that has probably happened. I've heard that it was incorporated into the vehicle handling dynamics system - electronic stability control - but not totally sure if that ever happened or not.
I am almost 100% sure the ABCM has a "tattle tale" feature residing in its deepest areas. This will record throttle opening, vehicle speed, G-forces in all directions and brake applications. Normally it will record the last 300 seconds prior to impact because the engineer wants to know how the car was being driven prior to the crash. It is a first in, first out - "FIFO"- application, continually discarding the old while recording the new. Our information was not available to the service industry but it was a privilege reserved for the engineering community for protection against lawsuits as well as recording what happened so we could make improvements accordingly. Big Brother is alive and well - even decades ago! LOL!
Once again - consult your service manual. If not comfortable or if you do not posses above average mechanical skills, take it to a shop.
Sorry for the rant - brought back a lot of memories - LOL!
Good luck!
Jake
First thing - get a factory service manual and follow the instruction therein. You are going to find the FSM very useful in repairing other crash areas so might as well spend the bucks and spring for one.
Very important: Disconnect the battery and wait about a minute prior to doing any work on anything. The air bag control module - ABCM - has charged capacitors which will supply current to deploy the air bags even if the battery is the first thing destroyed in a crash sequence. So even without battery power, the air bag system will still function normally for a couple of seconds during a crash environment. Generally the capacitors will discharge in just a few seconds but it is best to be safe and wait one minute before doing any work.
My knowledge is old school and I certainly am not an expert on your specific vehicle but we used two sensors to control deployment of the air bags. One is a "G-sensor" located inside the airbag control module itself and the other is called a "safeing-sensor" and it is located near the front if the car. Both sensors must activate simultaneously prior to the air bags being deployed. We didn't want some jerk to be able to deploy the airbag with a sledge hammer pounding on the front bumper area. Usually there are two safeing-sensors, one at each front corner of the vehicle. The Air Bag Control Module itself is usually located in the vehicle in an area which is not commonly damaged in a crash. We located the ABCM on the tunnel just behind the shifter. I have no idea where yours is located. Consult the FSM.
The safeing-sensors up front are almost always destroyed in a crash so most likely, you will have to replace them. If the Air Bag Control Module is not damaged, you will probably be ok to use it again.
Using the FSM, be absolutely positive there are no wires which have been damaged as a result of the crash. With the battery still disconnected, install the replacement parts as required. Tighten all fasteners securely - do not let the sensors or module just dangle from the wires. Secure everything - period. The electrical connectors to the various sensors are gold plated to insure excellent reliability over an extended time frame so do not use substitutes. If a connector appears to have been damaged, replace it with the gold plated parts.
What we used to do as the final step was to position the ignition switch to the run position and then connect the vehicle battery as the last event. If the system is defective and the air bag deploys, then it is best that you are outside the vehicle.
Some other folks used to install everything except the airbags themselves and then using a scan tool, check things for codes. There will be an airbag disconnect/continuity code for sure but by using the scan tool it was possible to safely ferret out any other problems without the danger of an airbag deployment. If there are no codes other than the airbag continuity ones, then you can once again disconnect the battery and after waiting a minute or two, install the air bags. Some guys used to leave the ignition key off and after connecting the battery, rotate the ignition key while remaining as low as possible in the passenger seat. That always scared me - it was beyond my "chicken limit" so I did it all from outside the car.
The airbag system does its obligatory system check when the key is cycled to the on position and there should be a bulb check light for a few seconds. If there is no warning lamp illuminated after the bulb check, then you are good to go. The airbag diagnostics are quite complicated and are very reliable - undoubtedly the most reliable feature on the car - well, guess that ABS brakes rank right up there too. If the lamp comes on as it should for the bulb check during the initial key on episode and then goes out, everything is ok. If the bulb check doesn't work or if the lamp stays illuminated, then something is wrong and my advice is do not drive the vehicle until the system has been repaired.
Undoubtedly your car has airbag dust all over the place. Airbags are pyrotechnic and use sodium azide as the explosive charge to generate the gases required to inflate the airbag. By itself, sodium azide is quite nasty stuff but when the bag deploys, the sodium azide reacts with moisture in the atmosphere and within milliseconds it becomes inert. But having said that, my advice is to not inhale anymore of the stuff than you have to. Use a mask and goggles and gloves when vacuuming the residue out.
Like eluded to prior, this information is dated. There was investigation into combining the sensors into a single module and that has probably happened. I've heard that it was incorporated into the vehicle handling dynamics system - electronic stability control - but not totally sure if that ever happened or not.
I am almost 100% sure the ABCM has a "tattle tale" feature residing in its deepest areas. This will record throttle opening, vehicle speed, G-forces in all directions and brake applications. Normally it will record the last 300 seconds prior to impact because the engineer wants to know how the car was being driven prior to the crash. It is a first in, first out - "FIFO"- application, continually discarding the old while recording the new. Our information was not available to the service industry but it was a privilege reserved for the engineering community for protection against lawsuits as well as recording what happened so we could make improvements accordingly. Big Brother is alive and well - even decades ago! LOL!
Once again - consult your service manual. If not comfortable or if you do not posses above average mechanical skills, take it to a shop.
Sorry for the rant - brought back a lot of memories - LOL!
Good luck!
Jake
Team Owner
Joined: Sep 2003
Posts: 25,393
Likes: 2,741
You mentioned BAGS and the '93 is a single bag system.
What year is the "parts car" purchase? When you remove the deployed bag the most common failure in addition to is the coil/clock spring. That's normally visible damage if it's damaged. The yellow wire connecting it to the air bag will be burnt and that damage will likely be visible. A '93 DERM is peculiar to late '92 and '93 MY cars. It will likely have 16177277 label on it and I would think you should use only that one. A '92 with a label 16176561 MIGHT work but a '92 with 16081221 would be considered a "NO FIT". The DERM is generally a required replacement with any deployment on the earlier SIR systems. Diagnostic codes would dictate any others that need replacement. '91 thru '93 MY coil/clock spring is the same. The label on the coils should match one another. If NOT check and confirm. The coil/clock spring can generally be confirmed as useable by a simple continuity check, in a collision repair environment in a shop environment it was sometimes considered a "requirement". I believe the FSM will mention diagnostic codes only need to be addressed but then in a "closing comment" it was always mentioned I believe that when in doubt replace it all.
SIR is pretty straight forward. A FSM and you should be good to go.
What year is the "parts car" purchase? When you remove the deployed bag the most common failure in addition to is the coil/clock spring. That's normally visible damage if it's damaged. The yellow wire connecting it to the air bag will be burnt and that damage will likely be visible. A '93 DERM is peculiar to late '92 and '93 MY cars. It will likely have 16177277 label on it and I would think you should use only that one. A '92 with a label 16176561 MIGHT work but a '92 with 16081221 would be considered a "NO FIT". The DERM is generally a required replacement with any deployment on the earlier SIR systems. Diagnostic codes would dictate any others that need replacement. '91 thru '93 MY coil/clock spring is the same. The label on the coils should match one another. If NOT check and confirm. The coil/clock spring can generally be confirmed as useable by a simple continuity check, in a collision repair environment in a shop environment it was sometimes considered a "requirement". I believe the FSM will mention diagnostic codes only need to be addressed but then in a "closing comment" it was always mentioned I believe that when in doubt replace it all.
SIR is pretty straight forward. A FSM and you should be good to go.
Last edited by WVZR-1; Jan 10, 2015 at 04:48 PM.
Thread Starter
Intermediate
Joined: Nov 2011
Posts: 29
Likes: 0
one airbag.
I was a vehicle crash engineer for a few years and have replaced a few of these and it is not rocket science. It has been a few decades so I will attempt to make this as generic as practical. Not sure if this applies to your car or not but here goes - LOL.
First thing - get a factory service manual and follow the instruction therein. You are going to find the FSM very useful in repairing other crash areas so might as well spend the bucks and spring for one.
Very important: Disconnect the battery and wait about a minute prior to doing any work on anything. The air bag control module - ABCM - has charged capacitors which will supply current to deploy the air bags even if the battery is the first thing destroyed in a crash sequence. So even without battery power, the air bag system will still function normally for a couple of seconds during a crash environment. Generally the capacitors will discharge in just a few seconds but it is best to be safe and wait one minute before doing any work.
My knowledge is old school and I certainly am not an expert on your specific vehicle but we used two sensors to control deployment of the air bags. One is a "G-sensor" located inside the airbag control module itself and the other is called a "safeing-sensor" and it is located near the front if the car. Both sensors must activate simultaneously prior to the air bags being deployed. We didn't want some jerk to be able to deploy the airbag with a sledge hammer pounding on the front bumper area. Usually there are two safeing-sensors, one at each front corner of the vehicle. The Air Bag Control Module itself is usually located in the vehicle in an area which is not commonly damaged in a crash. We located the ABCM on the tunnel just behind the shifter. I have no idea where yours is located. Consult the FSM.
The safeing-sensors up front are almost always destroyed in a crash so most likely, you will have to replace them. If the Air Bag Control Module is not damaged, you will probably be ok to use it again.
Using the FSM, be absolutely positive there are no wires which have been damaged as a result of the crash. With the battery still disconnected, install the replacement parts as required. Tighten all fasteners securely - do not let the sensors or module just dangle from the wires. Secure everything - period. The electrical connectors to the various sensors are gold plated to insure excellent reliability over an extended time frame so do not use substitutes. If a connector appears to have been damaged, replace it with the gold plated parts.
What we used to do as the final step was to position the ignition switch to the run position and then connect the vehicle battery as the last event. If the system is defective and the air bag deploys, then it is best that you are outside the vehicle.
Some other folks used to install everything except the airbags themselves and then using a scan tool, check things for codes. There will be an airbag disconnect/continuity code for sure but by using the scan tool it was possible to safely ferret out any other problems without the danger of an airbag deployment. If there are no codes other than the airbag continuity ones, then you can once again disconnect the battery and after waiting a minute or two, install the air bags. Some guys used to leave the ignition key off and after connecting the battery, rotate the ignition key while remaining as low as possible in the passenger seat. That always scared me - it was beyond my "chicken limit" so I did it all from outside the car.
The airbag system does its obligatory system check when the key is cycled to the on position and there should be a bulb check light for a few seconds. If there is no warning lamp illuminated after the bulb check, then you are good to go. The airbag diagnostics are quite complicated and are very reliable - undoubtedly the most reliable feature on the car - well, guess that ABS brakes rank right up there too. If the lamp comes on as it should for the bulb check during the initial key on episode and then goes out, everything is ok. If the bulb check doesn't work or if the lamp stays illuminated, then something is wrong and my advice is do not drive the vehicle until the system has been repaired.
Undoubtedly your car has airbag dust all over the place. Airbags are pyrotechnic and use sodium azide as the explosive charge to generate the gases required to inflate the airbag. By itself, sodium azide is quite nasty stuff but when the bag deploys, the sodium azide reacts with moisture in the atmosphere and within milliseconds it becomes inert. But having said that, my advice is to not inhale anymore of the stuff than you have to. Use a mask and goggles and gloves when vacuuming the residue out.
Like eluded to prior, this information is dated. There was investigation into combining the sensors into a single module and that has probably happened. I've heard that it was incorporated into the vehicle handling dynamics system - electronic stability control - but not totally sure if that ever happened or not.
I am almost 100% sure the ABCM has a "tattle tale" feature residing in its deepest areas. This will record throttle opening, vehicle speed, G-forces in all directions and brake applications. Normally it will record the last 300 seconds prior to impact because the engineer wants to know how the car was being driven prior to the crash. It is a first in, first out - "FIFO"- application, continually discarding the old while recording the new. Our information was not available to the service industry but it was a privilege reserved for the engineering community for protection against lawsuits as well as recording what happened so we could make improvements accordingly. Big Brother is alive and well - even decades ago! LOL!
Once again - consult your service manual. If not comfortable or if you do not posses above average mechanical skills, take it to a shop.
Sorry for the rant - brought back a lot of memories - LOL!
Good luck!
Jake
First thing - get a factory service manual and follow the instruction therein. You are going to find the FSM very useful in repairing other crash areas so might as well spend the bucks and spring for one.
Very important: Disconnect the battery and wait about a minute prior to doing any work on anything. The air bag control module - ABCM - has charged capacitors which will supply current to deploy the air bags even if the battery is the first thing destroyed in a crash sequence. So even without battery power, the air bag system will still function normally for a couple of seconds during a crash environment. Generally the capacitors will discharge in just a few seconds but it is best to be safe and wait one minute before doing any work.
My knowledge is old school and I certainly am not an expert on your specific vehicle but we used two sensors to control deployment of the air bags. One is a "G-sensor" located inside the airbag control module itself and the other is called a "safeing-sensor" and it is located near the front if the car. Both sensors must activate simultaneously prior to the air bags being deployed. We didn't want some jerk to be able to deploy the airbag with a sledge hammer pounding on the front bumper area. Usually there are two safeing-sensors, one at each front corner of the vehicle. The Air Bag Control Module itself is usually located in the vehicle in an area which is not commonly damaged in a crash. We located the ABCM on the tunnel just behind the shifter. I have no idea where yours is located. Consult the FSM.
The safeing-sensors up front are almost always destroyed in a crash so most likely, you will have to replace them. If the Air Bag Control Module is not damaged, you will probably be ok to use it again.
Using the FSM, be absolutely positive there are no wires which have been damaged as a result of the crash. With the battery still disconnected, install the replacement parts as required. Tighten all fasteners securely - do not let the sensors or module just dangle from the wires. Secure everything - period. The electrical connectors to the various sensors are gold plated to insure excellent reliability over an extended time frame so do not use substitutes. If a connector appears to have been damaged, replace it with the gold plated parts.
What we used to do as the final step was to position the ignition switch to the run position and then connect the vehicle battery as the last event. If the system is defective and the air bag deploys, then it is best that you are outside the vehicle.
Some other folks used to install everything except the airbags themselves and then using a scan tool, check things for codes. There will be an airbag disconnect/continuity code for sure but by using the scan tool it was possible to safely ferret out any other problems without the danger of an airbag deployment. If there are no codes other than the airbag continuity ones, then you can once again disconnect the battery and after waiting a minute or two, install the air bags. Some guys used to leave the ignition key off and after connecting the battery, rotate the ignition key while remaining as low as possible in the passenger seat. That always scared me - it was beyond my "chicken limit" so I did it all from outside the car.
The airbag system does its obligatory system check when the key is cycled to the on position and there should be a bulb check light for a few seconds. If there is no warning lamp illuminated after the bulb check, then you are good to go. The airbag diagnostics are quite complicated and are very reliable - undoubtedly the most reliable feature on the car - well, guess that ABS brakes rank right up there too. If the lamp comes on as it should for the bulb check during the initial key on episode and then goes out, everything is ok. If the bulb check doesn't work or if the lamp stays illuminated, then something is wrong and my advice is do not drive the vehicle until the system has been repaired.
Undoubtedly your car has airbag dust all over the place. Airbags are pyrotechnic and use sodium azide as the explosive charge to generate the gases required to inflate the airbag. By itself, sodium azide is quite nasty stuff but when the bag deploys, the sodium azide reacts with moisture in the atmosphere and within milliseconds it becomes inert. But having said that, my advice is to not inhale anymore of the stuff than you have to. Use a mask and goggles and gloves when vacuuming the residue out.
Like eluded to prior, this information is dated. There was investigation into combining the sensors into a single module and that has probably happened. I've heard that it was incorporated into the vehicle handling dynamics system - electronic stability control - but not totally sure if that ever happened or not.
I am almost 100% sure the ABCM has a "tattle tale" feature residing in its deepest areas. This will record throttle opening, vehicle speed, G-forces in all directions and brake applications. Normally it will record the last 300 seconds prior to impact because the engineer wants to know how the car was being driven prior to the crash. It is a first in, first out - "FIFO"- application, continually discarding the old while recording the new. Our information was not available to the service industry but it was a privilege reserved for the engineering community for protection against lawsuits as well as recording what happened so we could make improvements accordingly. Big Brother is alive and well - even decades ago! LOL!
Once again - consult your service manual. If not comfortable or if you do not posses above average mechanical skills, take it to a shop.
Sorry for the rant - brought back a lot of memories - LOL!
Good luck!
Jake
thanks thats a lot of detail, much appreciated.
and i know theres just one air bag both are a '93 it was my bad adding the "s" on there haha.
