Potentially very dangerous SRS wiring problem?
MyOwnMechanic
02-12-2005, 05:43 PM
I have a 2003 Odyssey LX with 42K miles - beyond warranty. I had an intermittent problem with the SRS light going on and off. Then I had a problem with the SRS light staying on. And then I noticed my horn and my cruise control did not work. I also purchased a Factory Service Manual so I could do this right.
Skipping the details, I determined that the "cable reel" in my steering column was defective... the connections from the steering column did not connect. The crunching noise in the steering column was another hint.
The "cable reel" is a special order part, so I disconnected all wires into the steering wheel just to be sure that wiring weirdness would not deploy the steering wheel air bag before I received the part.
I replaced the cable reel today, and I am really upset at what I saw.
Here are some pictures:
http://files.automotiveforums.com/gallery/watermark.php?file=/503/300716HondaCableReelSmall.jpg
http://files.automotiveforums.com/gallery/watermark.php?file=/503/300716HondaCableReelWireCloseUpSmll.JPG
I am sooo glad I disconnected all the wires into the steering wheel earlier. The ribbon cable had broken off, and any of the connectors could have potentially shorted with any of the contacts to the steering wheel. These connectors include the trigger for the Steering Wheel Air Bag!!!
Could a wrong connnection have caused the airbag to suddenly deploy? The Honda Factory Service Manual has plenty of warnings about taking great care with SRS wires to be sure you don't deploy the bags.
I have filed a complaint with the ODI (Office of Defects Investigation) at the NHTSA about this. This requires investigation to see if it is a serious problem, a problem that might occur in other cars. If it can cause an SRS Air Bag to deploy, then fixing it could only save lives.
My second pursuit on this is whether or not the new part I just installed might share the same problem. Do I tell my wife not to steer the car so she doesn't wear the part out? I will notify Honda as well.
Stay tuned, I will report on news about this as it happens.
Skipping the details, I determined that the "cable reel" in my steering column was defective... the connections from the steering column did not connect. The crunching noise in the steering column was another hint.
The "cable reel" is a special order part, so I disconnected all wires into the steering wheel just to be sure that wiring weirdness would not deploy the steering wheel air bag before I received the part.
I replaced the cable reel today, and I am really upset at what I saw.
Here are some pictures:
http://files.automotiveforums.com/gallery/watermark.php?file=/503/300716HondaCableReelSmall.jpg
http://files.automotiveforums.com/gallery/watermark.php?file=/503/300716HondaCableReelWireCloseUpSmll.JPG
I am sooo glad I disconnected all the wires into the steering wheel earlier. The ribbon cable had broken off, and any of the connectors could have potentially shorted with any of the contacts to the steering wheel. These connectors include the trigger for the Steering Wheel Air Bag!!!
Could a wrong connnection have caused the airbag to suddenly deploy? The Honda Factory Service Manual has plenty of warnings about taking great care with SRS wires to be sure you don't deploy the bags.
I have filed a complaint with the ODI (Office of Defects Investigation) at the NHTSA about this. This requires investigation to see if it is a serious problem, a problem that might occur in other cars. If it can cause an SRS Air Bag to deploy, then fixing it could only save lives.
My second pursuit on this is whether or not the new part I just installed might share the same problem. Do I tell my wife not to steer the car so she doesn't wear the part out? I will notify Honda as well.
Stay tuned, I will report on news about this as it happens.
lorunner
02-12-2005, 07:06 PM
As far as the bag deploying from a short in the cable real its impossible. The real has no power going through it. The horn works by the horn plate grounding along with the cruise controls wich send ground to the control unit. The casution in the manual is to warn you that if you accidentally provide pover to the wires yourself that it may deploy the bag.
The bag by itself is totally safe because it will only deploy when power and ground are given to it.
The bag by itself is totally safe because it will only deploy when power and ground are given to it.
MyOwnMechanic
02-12-2005, 08:30 PM
As far as the bag deploying from a short in the cable real its impossible. The real has no power going through it.
The horn works by the horn plate grounding...
The horn relay, an inductor, connects to the horn button. When the horn is not being used it has 12 volts. The cruise control buttons on the steering wheel use this POWER to send signals to the cruise control activator unit, and I suspect to light those little lights on the buttons, too.
So there is 12 volts going into the horn through the cable reel. The question is of imedance - what is the impedance of the horn relay versus the air bag. If they are about equal, each will see 6 volts of power at steady state. Is 6 volts enough to set off the Air Bag? I can't answer these questions, but it requires more detailed knowledge to make that claim.
There is also transient voltage... If the air bag deployment wire were to connect with the horn relay wire, the air bag wire would see 12 volts for at least a miniscule moment. The voltage may drop so quickly that it would not set off the air bag. I can't answer these questions, but it requires more detailed knowledge to make that claim.
It is possible Honda may have designed the system so that if the airbag wires were connected to the horn relay and ground, the air bag would not deploy. It is possible that they did not design aginast this possibility too. Even if they did this design with the original airbags, newer "smart" airbags take variable inputs so that they can deploy more or less. If the newer airbags take less to deploy, then there could be an issue.
It is possible that both airbag wires could have been accidentally connected to a ground and the horn relay. It will take an engineering level answer to know whether or not there was ANY CHANCE of the air bag deploying under this condition.
The horn works by the horn plate grounding...
The horn relay, an inductor, connects to the horn button. When the horn is not being used it has 12 volts. The cruise control buttons on the steering wheel use this POWER to send signals to the cruise control activator unit, and I suspect to light those little lights on the buttons, too.
So there is 12 volts going into the horn through the cable reel. The question is of imedance - what is the impedance of the horn relay versus the air bag. If they are about equal, each will see 6 volts of power at steady state. Is 6 volts enough to set off the Air Bag? I can't answer these questions, but it requires more detailed knowledge to make that claim.
There is also transient voltage... If the air bag deployment wire were to connect with the horn relay wire, the air bag wire would see 12 volts for at least a miniscule moment. The voltage may drop so quickly that it would not set off the air bag. I can't answer these questions, but it requires more detailed knowledge to make that claim.
It is possible Honda may have designed the system so that if the airbag wires were connected to the horn relay and ground, the air bag would not deploy. It is possible that they did not design aginast this possibility too. Even if they did this design with the original airbags, newer "smart" airbags take variable inputs so that they can deploy more or less. If the newer airbags take less to deploy, then there could be an issue.
It is possible that both airbag wires could have been accidentally connected to a ground and the horn relay. It will take an engineering level answer to know whether or not there was ANY CHANCE of the air bag deploying under this condition.
lorunner
02-13-2005, 10:54 AM
The horn switch in the steering wheel is a ground curcuit. When you pust the button ground is sent from the wheel werer it gets ground through the column into the button, through the reel and into the multiplex. The multiplex then grounds the relay and the relay sends power to the horns. Any voltage that you are seeing or may see is just blead through from the curcuit but will not carry enough amperage to light a test light or cause an airbag to fire.
The same goes for the cruise control. Its all ground that is sent to the cruise control unit
As for lights on the cruise buttons i don't know where you are getting this from because none of the buttons on the wheel light up. Wether it be cruise or audio they do not have lights.
Most importantly i think the biggest issue here is that your not recognizing that the SRS control unit gives the air bag both power and ground to fire the bag. Its not as if the ground side is always grounded and it just adds power. So the percentage of a short in the reel were both wires on the bag would find power and ground simaltaniously and find it on the right wires i think is slim to none.
The same goes for the cruise control. Its all ground that is sent to the cruise control unit
As for lights on the cruise buttons i don't know where you are getting this from because none of the buttons on the wheel light up. Wether it be cruise or audio they do not have lights.
Most importantly i think the biggest issue here is that your not recognizing that the SRS control unit gives the air bag both power and ground to fire the bag. Its not as if the ground side is always grounded and it just adds power. So the percentage of a short in the reel were both wires on the bag would find power and ground simaltaniously and find it on the right wires i think is slim to none.
MyOwnMechanic
02-13-2005, 01:01 PM
So the percentage of a short in the reel were both wires on the bag would find power and ground simaltaniously and find it on the right wires i think is slim to none.
On analysis I agree the likelihood is very slim. It was the large amount of exposed copper, and that the ribbon cable did not seem to stay aligned that makes me think the chances are greater than zero.
...Any voltage that you are seeing or may see is just blead through from the curcuit but will not carry enough amperage to light a test light or cause an airbag to fire.
That is what I hope is true. Do you know of something published by Honda or the airbag manufacturer that explicitly states this? No offense meant, but I'd like to rest my conclusions on something more than a public forum discussion when this level of safety is concerned.
I am still puzzling how a 2 year old car with 42,000 miles (6K beyond warranty) can have such a failure in the steering column wiring. The replacement part was special order, thus it is probably not a common failure, at least not yet.
I was also annoyed when I spoke to a Honda service manager to see if Honda would cover the repair. Instead he insisted that I get the trouble codes read ($70) and insisted that the horn problem and the SRS problems were co-incidental. And it would require two trips since the cable reel is a special order part. Sure, the service manager is no mechanic, but there was no way to get around him either.
On analysis I agree the likelihood is very slim. It was the large amount of exposed copper, and that the ribbon cable did not seem to stay aligned that makes me think the chances are greater than zero.
...Any voltage that you are seeing or may see is just blead through from the curcuit but will not carry enough amperage to light a test light or cause an airbag to fire.
That is what I hope is true. Do you know of something published by Honda or the airbag manufacturer that explicitly states this? No offense meant, but I'd like to rest my conclusions on something more than a public forum discussion when this level of safety is concerned.
I am still puzzling how a 2 year old car with 42,000 miles (6K beyond warranty) can have such a failure in the steering column wiring. The replacement part was special order, thus it is probably not a common failure, at least not yet.
I was also annoyed when I spoke to a Honda service manager to see if Honda would cover the repair. Instead he insisted that I get the trouble codes read ($70) and insisted that the horn problem and the SRS problems were co-incidental. And it would require two trips since the cable reel is a special order part. Sure, the service manager is no mechanic, but there was no way to get around him either.
badbrakes
02-13-2005, 04:18 PM
great post... make sure you keep us updated on that problem.
About your Factory Service Manual, where did u get it ? How much ? I have been trying to get one from eBay or the likes but couldn't find one (not surprinsgly since vehicle is fairly new).
About your Factory Service Manual, where did u get it ? How much ? I have been trying to get one from eBay or the likes but couldn't find one (not surprinsgly since vehicle is fairly new).
lorunner
02-13-2005, 04:25 PM
I know this because i am a trained honda tech for 10 years. I studdied the wiring diagrams before i responded to your post. I also diagnosed many horn problems along with cruise control problems and i can tell you that there is no power in the wheel. All the funtions send a ground.
I have also had many dealings with the Honda technical support people with diagnosis of other curcuits were i too have found 12 volts (with a DVOM) on what is supposed to be a ground curcuit and they have told me the same thing which is what im telling you. If you were to hook up a test lite there isn't enough amperage to light the lite. The power isn't there its just residual bleeding into the curcuit.
I can tell you this i have diagnosed only one SRS reel on an 02 Ody. for an intermitant code. and we had another one last week too.
I understand your concern and i take no offense in your responses. I just want you to know that i am trying to help and thats all. I am not trying to bullshit you im just trying to help you understand the facts. If i had the means to i would fax you over the schematics so you could review them yourself and maybe that would put you mind at ease.
Off the topic. How did you get pictures displayed in your post? I have been trying to do this for a long time but haven't figured it out yet.
I have also had many dealings with the Honda technical support people with diagnosis of other curcuits were i too have found 12 volts (with a DVOM) on what is supposed to be a ground curcuit and they have told me the same thing which is what im telling you. If you were to hook up a test lite there isn't enough amperage to light the lite. The power isn't there its just residual bleeding into the curcuit.
I can tell you this i have diagnosed only one SRS reel on an 02 Ody. for an intermitant code. and we had another one last week too.
I understand your concern and i take no offense in your responses. I just want you to know that i am trying to help and thats all. I am not trying to bullshit you im just trying to help you understand the facts. If i had the means to i would fax you over the schematics so you could review them yourself and maybe that would put you mind at ease.
Off the topic. How did you get pictures displayed in your post? I have been trying to do this for a long time but haven't figured it out yet.
MyOwnMechanic
02-13-2005, 04:30 PM
About your Factory Service Manual, where did u get it ? How much?
Online: $72 at H and A Accessories:
http://www.handaaccessories.com/odymaint02.html
I could not find an email address or other on-line location to contact Honda directly, so I'll probably send them snail mail. And NHTSA is good but I doubt they are fast - it may take time to learn anything for sure.
Online: $72 at H and A Accessories:
http://www.handaaccessories.com/odymaint02.html
I could not find an email address or other on-line location to contact Honda directly, so I'll probably send them snail mail. And NHTSA is good but I doubt they are fast - it may take time to learn anything for sure.
MyOwnMechanic
02-14-2005, 02:51 AM
Just did a search and turned up a recall on the cable reel for some 2002, 2003 and 2004 CR-Vs.
see http://honda.samswope.com/Recall.aspx
It says here that:
"There is a new Recall Notice for all 2002, 2003 & select 2004 CR-V's with VIN's beginning with SHSRD concerning the SRS Cable Reel Connectors."
The plot thickens!
see http://honda.samswope.com/Recall.aspx
It says here that:
"There is a new Recall Notice for all 2002, 2003 & select 2004 CR-V's with VIN's beginning with SHSRD concerning the SRS Cable Reel Connectors."
The plot thickens!
lorunner
02-14-2005, 03:44 PM
Just did a search and turned up a recall on the cable reel for some 2002, 2003 and 2004 CR-Vs.
see http://honda.samswope.com/Recall.aspx
It says here that:
"There is a new Recall Notice for all 2002, 2003 & select 2004 CR-V's with VIN's beginning with SHSRD concerning the SRS Cable Reel Connectors."
The plot thickens!
Right it has to do with incorrect wiring at the yellow SRS conector. The wiring order is backwards and the bag can deploy improperly. Example if its a light impact the wrong stage may go off. The control unit will tell the first stage to fire but since the wiring is bacwards the second stage will go off instead.
It has nothing to do with the reel itself other than that.
see http://honda.samswope.com/Recall.aspx
It says here that:
"There is a new Recall Notice for all 2002, 2003 & select 2004 CR-V's with VIN's beginning with SHSRD concerning the SRS Cable Reel Connectors."
The plot thickens!
Right it has to do with incorrect wiring at the yellow SRS conector. The wiring order is backwards and the bag can deploy improperly. Example if its a light impact the wrong stage may go off. The control unit will tell the first stage to fire but since the wiring is bacwards the second stage will go off instead.
It has nothing to do with the reel itself other than that.
MyOwnMechanic
02-25-2005, 10:06 PM
An update - actually the NHTSA contacted me quickly on Monday and requested I send them the broken part. They received the part that Wednesday. And they will get back to me with any conclusions, etc. I am sure that will take time.
They said it was very unusual to have someone bring these kinds of problems to their attention. Usually the problems are dealt with directly by the dealers and they don't hear about it. Suggests that many defects may not get uncovered since the information is never aggregated and then made public. Is it better to leave this kind of tracking only up to the manufacturers? I believe they should be trusted, but some oversight is still necessary. For example I doubt whether Honda could tell me whether to expect this part will cause me problems again or not... corporations aren't very good at making these kinds of decisions.
Regarding the SRS light, on the 2003 (and newer) Odys the light does not need to be reset. It turns off automatically when there is no problem detected. The SRS control unit still remembers the trouble code for this problem, but I don't care. A Honda proprietary tool is needed to look at or reset/erase trouble codes on the SRS control unit.
They said it was very unusual to have someone bring these kinds of problems to their attention. Usually the problems are dealt with directly by the dealers and they don't hear about it. Suggests that many defects may not get uncovered since the information is never aggregated and then made public. Is it better to leave this kind of tracking only up to the manufacturers? I believe they should be trusted, but some oversight is still necessary. For example I doubt whether Honda could tell me whether to expect this part will cause me problems again or not... corporations aren't very good at making these kinds of decisions.
Regarding the SRS light, on the 2003 (and newer) Odys the light does not need to be reset. It turns off automatically when there is no problem detected. The SRS control unit still remembers the trouble code for this problem, but I don't care. A Honda proprietary tool is needed to look at or reset/erase trouble codes on the SRS control unit.
Rufnusd
02-25-2005, 11:51 PM
The SRS lights dont turn off automatically. ex: If you remove a seat in the Ody, Civic, Accord----or just about every vehicle Honda makes that has SRS harnesses on it and cycle the ignition...guess what??? it stays on.... no doubt. It can be reset, but until it is reset, it stays on. There are other examples of this if need be.
MyOwnMechanic
02-26-2005, 11:22 AM
The SRS lights dont turn off automatically. ex: <...> There are other examples of this if need be.
I know that was true for 2002 and before. The FSM shows very different SRS wiring for 2003 onward.
I did NOT reset my SRS light, and it is now OFF. Maybe there are cases on the 2003 that the light requires a reset, however there doesn't appear to be such a procedure in the FSM for the 2003 either, only a procedure to clear the control unit's memory of trouble codes. Factory Service Manuals are not always complete. It may depends on the cause of the light going on in the first place.
I know that was true for 2002 and before. The FSM shows very different SRS wiring for 2003 onward.
I did NOT reset my SRS light, and it is now OFF. Maybe there are cases on the 2003 that the light requires a reset, however there doesn't appear to be such a procedure in the FSM for the 2003 either, only a procedure to clear the control unit's memory of trouble codes. Factory Service Manuals are not always complete. It may depends on the cause of the light going on in the first place.
apopto5
08-21-2005, 07:35 PM
I have been searching the forum and have yet to find the answer to my question. I left the interior light on over night in my 2001
Odyssey and it was sufficient to drain the original battery. I jump started it the next morning, but the SRS light stayed illuminated. I have found some posting on the internet that indicate there is some issues with the SRS system and low battery voltage.
I do not beleive there is ant issues with my SRS system, and want to reset it. Is there a method to clear the SRS light and have the system do a re-check.
Odyssey and it was sufficient to drain the original battery. I jump started it the next morning, but the SRS light stayed illuminated. I have found some posting on the internet that indicate there is some issues with the SRS system and low battery voltage.
I do not beleive there is ant issues with my SRS system, and want to reset it. Is there a method to clear the SRS light and have the system do a re-check.
MyOwnMechanic
08-28-2005, 01:16 AM
I left the interior light on over night in my 2001
Odyssey and it was sufficient to drain the original battery. I jump started it the next morning, but the SRS light stayed illuminated. I have found some posting on the internet that indicate there is some issues with the SRS system and low battery voltage.
I do not beleive there is ant issues with my SRS system, and want to reset it. Is there a method to clear the SRS light and have the system do a re-check.
The 99-02 Odysseys have an "MES connector" - Memroy Erase Signal. 03 and 04 don't. Erasing memory requires a proprietary diagnostic tool. On the '03 the light does go off if the problem goes away... but the trouble code remains stored. I don't know if the '99-02 goes out automatically too, or if it stays on until the memory is cleared.
I have read that other Honda's have the MES too. It is a two pin connector that is part of the SRS harness (the yellow stuff you are warned not to touch) and hangs out to the left of the emergency brake pedal somewhere. To reset the SRS light requires connecting/disconnecting the two pins. The manual says not to use a jumper wire, but some special connector thingy. I have no experience with any of this, I just can read the manual. Maybe the proprietary connector has some resistance in it?
Odyssey and it was sufficient to drain the original battery. I jump started it the next morning, but the SRS light stayed illuminated. I have found some posting on the internet that indicate there is some issues with the SRS system and low battery voltage.
I do not beleive there is ant issues with my SRS system, and want to reset it. Is there a method to clear the SRS light and have the system do a re-check.
The 99-02 Odysseys have an "MES connector" - Memroy Erase Signal. 03 and 04 don't. Erasing memory requires a proprietary diagnostic tool. On the '03 the light does go off if the problem goes away... but the trouble code remains stored. I don't know if the '99-02 goes out automatically too, or if it stays on until the memory is cleared.
I have read that other Honda's have the MES too. It is a two pin connector that is part of the SRS harness (the yellow stuff you are warned not to touch) and hangs out to the left of the emergency brake pedal somewhere. To reset the SRS light requires connecting/disconnecting the two pins. The manual says not to use a jumper wire, but some special connector thingy. I have no experience with any of this, I just can read the manual. Maybe the proprietary connector has some resistance in it?
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