C5 Tech Corvette Tech/Performance: LS1 Corvette Technical Info, Internal Engine, External Engine, Tech Topics, Basic Tech, Maintenance, How to Remove & Replace
Sponsored by:
Sponsored by:

DTC B0026 LF/Driver Frontal Deployment Loop (Single Stage or Stage 1) Open

Old 07-03-2007, 03:39 AM
  #1  
Camaroguy22
Instructor
Thread Starter
 
Camaroguy22's Avatar
 
Member Since: Jun 2006
Location: Gambrills Maryland
Posts: 241
Likes: 0
Received 0 Likes on 0 Posts
Default DTC B0026 LF/Driver Frontal Deployment Loop (Single Stage or Stage 1) Open

I decided to make this problem have its own thread.

Can you guys help me fix this? My car is throwing that code. Only symptoms are the horn doesn't work if you press on it from the steering wheel...however the horn works when the alarm sounds.
Old 07-05-2007, 02:13 PM
  #2  
Camaroguy22
Instructor
Thread Starter
 
Camaroguy22's Avatar
 
Member Since: Jun 2006
Location: Gambrills Maryland
Posts: 241
Likes: 0
Received 0 Likes on 0 Posts
Default

Bump! Need Help!!!
Old 07-05-2007, 04:12 PM
  #3  
runamuk
Le Mans Master
 
runamuk's Avatar
 
Member Since: Jul 2002
Location: Slave to the evil empire
Posts: 7,364
Received 3 Likes on 2 Posts
Cruise-In V Veteran
St. Jude Donor '04

Default

Sounds to me like the switch in the steering wheel is open, The switch is actually 2 seperate metallic strips inside the airbag cover.

I don't have my service manual in front of me but from your description thats the only thing I can think of.
Old 07-05-2007, 04:47 PM
  #4  
BlackZ06
Safety Car
 
BlackZ06's Avatar
 
Member Since: Aug 2000
Location: San Rafael CA
Posts: 4,933
Likes: 0
Received 24 Likes on 19 Posts

Default

The Service Manual lists the following for DTC B0026 ....

------------------------------------------

Circuit Description

The steering wheel deployment loop consists of an inflatable restraint steering wheel module, an inflatable restraint steering wheel module coil, the steering wheel module - high control and steering wheel module - low control circuits. A shorting bar is used in the inflatable restraint steering wheel module and the inflatable restraint steering wheel module coil connectors which will short together the steering wheel module - high control and low control circuits when the connector is disconnected, this will help to prevent unwanted deployment of the inflator module during servicing. During a frontal crash of sufficient force the SDM will allow current to flow through the deployment loop in order to deploy the inflatable restraint steering wheel module. The SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, a DTC will store

Diagnostic Aids

Thouroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:

* An open or high resistance in the steering wheel module - high or low control circuits.

* A malfunctioning steering wheel module

* A malfunctioning steering wheel module coil

* An internal SDM malfunction

ACTIONS

1) Turn OFF ignition

2) Disconnect inflatable restraint steering wheel module coil connector

3) Inspect both sides of the harness for corrosion or damaged terminals

4) If damaged

5) Replace steering wheel module coil if connector is bad, replace harness if harness side is bad.

-------------------------------

If that doesn't fix it ... the rest of the diagnostics require a J 38715-A SIR Driver/Passenger Load Tool and a Tech2 to continue diagnosis. Basically the car will need to go to the dealer at this point. Even if you could determine that, for example, the SDM needs replacing .... the new SDM has to be programmed with your VIN using a Tech2 before your restraint system will work.

Personally the SIR (airbag) system scares the s**t out of me and is about the only problem area of the car that I guarantee I will take it to a dealer for service work. I don't mess with it .... an "unintended" deployment of the airbag will at least cost money (SDM and airbags have to be replaced .... parts alone well north of $1500) and has the real potential to seriously injure you if you are near the bag when it fires. I'd recommend that you STRONGLY consider taking this one to a dealer unless you have the service manuals to help step you through the SIR system.
Old 10-17-2007, 12:11 AM
  #5  
sks
Instructor
 
sks's Avatar
 
Member Since: Apr 2006
Location: Los Angeles CA
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
Default

do you know id there is a ground wire associated with this issue, code B0026. It is my only code and the airbag light is on. dont recall it being on before we messed with the ground wires.
Old 10-17-2007, 12:07 PM
  #6  
BlackZ06
Safety Car
 
BlackZ06's Avatar
 
Member Since: Aug 2000
Location: San Rafael CA
Posts: 4,933
Likes: 0
Received 24 Likes on 19 Posts

Default

The only GND I can see for the SIR system is a BLACK/WHITE wire from the SDM to Splice Pack 208, which is then grounded at G104 with a BLACK/WHITE wire. G104 is located on the frame almost directly below the battery.

Old 10-17-2007, 12:32 PM
  #7  
sks
Instructor
 
sks's Avatar
 
Member Since: Apr 2006
Location: Los Angeles CA
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
Default

Thanks. There was no airbag issue before we changed the harmonic balancer and messed with the ground wires. B0026 is my only code.

Will it cause a service engine soon light to come on?

Would pull the steering rack in changing the balancer cause this?

I think the manual says that it will disappear after 255 malfunction free iginition cycles have occurred. Perhaps the problem has been remedied and it needs to cycled more? Any other ways to ride it from the dash - reset wont work
Old 10-17-2007, 12:54 PM
  #8  
BlackZ06
Safety Car
 
BlackZ06's Avatar
 
Member Since: Aug 2000
Location: San Rafael CA
Posts: 4,933
Likes: 0
Received 24 Likes on 19 Posts

Default

Originally Posted by sks
Thanks. There was no airbag issue before we changed the harmonic balancer and messed with the ground wires. B0026 is my only code.

Will it cause a service engine soon light to come on?

Would pull the steering rack in changing the balancer cause this?

I think the manual says that it will disappear after 255 malfunction free iginition cycles have occurred. Perhaps the problem has been remedied and it needs to cycled more? Any other ways to ride it from the dash - reset wont work
The only warning a B0026 will light is the AIRBAG warning. You will not get a CHECK ENGINE indicator from it.

Ahhh .... pulled the steering rack .... did someone spin the steering wheel when it was disconnected from the steering box ???? There is a "clock spring" wire that connects the airbag to the electrical system. If the wheel turns too far, the wire will be broken, and that will set the B0026 DTC. What year is your car ????
Old 10-17-2007, 08:17 PM
  #9  
sks
Instructor
 
sks's Avatar
 
Member Since: Apr 2006
Location: Los Angeles CA
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
Default

a 2000 6speed. Its a "Service Engine Soon" light not "Check Engine" for the record.

So the wire could tear if someone spun the steering wheel while the steering rack was off? Just confirming.

If it is the wire would it tear by the steering wheel/column?

Thanks.
Old 10-18-2007, 08:03 AM
  #10  
runamuk
Le Mans Master
 
runamuk's Avatar
 
Member Since: Jul 2002
Location: Slave to the evil empire
Posts: 7,364
Received 3 Likes on 2 Posts
Cruise-In V Veteran
St. Jude Donor '04

Default

Originally Posted by sks
a 2000 6speed. Its a "Service Engine Soon" light not "Check Engine" for the record.

So the wire could tear if someone spun the steering wheel while the steering rack was off? Just confirming.

If it is the wire would it tear by the steering wheel/column?

Thanks.
Are you sure the message doesn't say "service vehicle soon" ?

BTW - I think BlackZ06 is right on the money with his diagnosis, I suspect the wheel was rotated when the rack was disconnected which broke the clockspring and now the drivers side airbag is showing a dead short to ground causing the B0026 code. I did the same thing.
Old 10-18-2007, 09:19 AM
  #11  
ajg1915
Race Director
Support Corvetteforum!
 
ajg1915's Avatar
 
Member Since: May 2005
Location: West Norriton PA
Posts: 15,958
Received 16 Likes on 15 Posts
St. Jude Donor '08

Default

Originally Posted by runamuk
Are you sure the message doesn't say "service vehicle soon" ?

BTW - I think BlackZ06 is right on the money with his diagnosis, I suspect the wheel was rotated when the rack was disconnected which broke the clockspring and now the drivers side airbag is showing a dead short to ground causing the B0026 code. I did the same thing.
The clock spring is the yellow circular piece in the steering column. Anytime you disconnect rack you should lock wheel inside to prevent the clockspring from being broke. Also helps with steering sensor alignment.
Old 10-18-2007, 12:44 PM
  #12  
sks
Instructor
 
sks's Avatar
 
Member Since: Apr 2006
Location: Los Angeles CA
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
Default

Yes service vehicle soon. sorry
Old 10-18-2007, 06:15 PM
  #13  
BlackZ06
Safety Car
 
BlackZ06's Avatar
 
Member Since: Aug 2000
Location: San Rafael CA
Posts: 4,933
Likes: 0
Received 24 Likes on 19 Posts

Default

Originally Posted by sks
a 2000 6speed. Its a "Service Engine Soon" light not "Check Engine" for the record.

So the wire could tear if someone spun the steering wheel while the steering rack was off? Just confirming.

If it is the wire would it tear by the steering wheel/column?

Thanks.
My parts manual shows the part number as 26069710, but when I enter that at vendor sites it comes up as invalid.

However, if you go to either ....

http://www.gmpartshouse.com

http://www.gmpartsdirect.com

And go into their on-line catalogs, you can find the part by selecting "Restraint System", then "Air Bag Componenets". then "clock spring" .... it is about an $80.00 part.

Basically think of it as a coiled wire. One end of the wire is attached to the "fixed" wiring harness, the other end is attached to the steering wheel airbag. As you turn the steering wheel the wire either coils tighter, or coils looser, depending on direction. The length of the wire is long enough to not tear at a full turn of the wheel, as the steering wheel will eventually stop when the steering rack reaches its maximum extension. However, if the steering column is detached from the steering rack, it is ossible to turn the steering wheel an unlimited number of times, and when that happens the coiled wire eventually reaches its limit and tears off its contacts.

If you have a MIL (Malfunction Indicator Light) showing on the IPC then you have another problem with the vehicle. Check for a DTC as ALMOST ALWAYS the MIL turns on when a Pxxxx DTC sets.

Be sure to disconnect the battery for AT LEAST 10 minutes before doing ANY work around the airbag system. The airbag system retains voltage so that should the battery immediately fail (disconnect) in a wreck, the airbag system has voltage to fire the bags when the SDM commands a firing.

Hope this helps (HTH)

Old 10-19-2007, 03:49 AM
  #14  
sks
Instructor
 
sks's Avatar
 
Member Since: Apr 2006
Location: Los Angeles CA
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
Default

Again thanks for the help. This is an annoying problem. I tried to find said clockspring and couldnt. I took pictures. Can you identify it for me ?

Is it hard to replace the spring? What tools/advice do you have assuming it is broken.

Name:  IMG_0713.jpg
Views: 19499
Size:  56.4 KB

Name:  IMG_0708.jpg
Views: 21022
Size:  60.0 KB

Name:  IMG_0706.jpg
Views: 17476
Size:  43.0 KB
Old 10-19-2007, 08:26 AM
  #15  
Plasticfan
Pro

 
Plasticfan's Avatar
 
Member Since: Jun 2007
Location: Joppa AL
Posts: 631
Likes: 0
Received 3 Likes on 1 Post

Default

BlackZ06 is is 100% correct here. The only thing I can add is your clockspring is under the steering wheel. Requires steering wheel removal to access it. It's a round yellow plastic piece about 3" in dia. Not shown in your pics. BTW, your drivers airbag is inop at this point. Be careful. HTH
Old 10-19-2007, 08:55 AM
  #16  
ajg1915
Race Director
Support Corvetteforum!
 
ajg1915's Avatar
 
Member Since: May 2005
Location: West Norriton PA
Posts: 15,958
Received 16 Likes on 15 Posts
St. Jude Donor '08

Default

You'll need a steering wheel puller.

Napa Auto Parts
You'll need the legs which are p/n 3510 $22.49, the puller which is p/n 2291 $19.09

Diconnect battery. Remove the center console, radio bezel and knee bolster.

In the passenger footwell remove the fuse marked for the SDM.

Under the steering wheel disconnect the yellow connectors (right side).
Old 10-19-2007, 10:48 AM
  #17  
sks
Instructor
 
sks's Avatar
 
Member Since: Apr 2006
Location: Los Angeles CA
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by ajg1915
You'll need a steering wheel puller.

Napa Auto Parts
You'll need the legs which are p/n 3510 $22.49, the puller which is p/n 2291 $19.09

Diconnect battery. Remove the center console, radio bezel and knee bolster.

In the passenger footwell remove the fuse marked for the SDM.

Under the steering wheel disconnect the yellow connectors (right side).
Thanks so so so so much.

1) I cannot pinpoint/see that this is the exact problem until i remove the steering wheel correct?

2) How long should this take?

3) What are the "legs"?

4) B0026 will cause a "service vehicle soon light"?

Get notified of new replies

To DTC B0026 LF/Driver Frontal Deployment Loop (Single Stage or Stage 1) Open

Old 10-19-2007, 10:51 AM
  #18  
BlackZ06
Safety Car
 
BlackZ06's Avatar
 
Member Since: Aug 2000
Location: San Rafael CA
Posts: 4,933
Likes: 0
Received 24 Likes on 19 Posts

Default

Originally Posted by sks
Thanks so so so so much.

1) I cannot pinpoint/see that this is the exact problem until i remove the steering wheel correct?

2) How long should this take?

3) What are the "legs"?

4) B0026 will cause a "service vehicle soon light"?
1) You have to remove the steering wheel to access the airbag clockspring

2) First time - probably 3 to 4 hours

3) the "legs" grip the steering wheel - go look at a puller at an auto store and you'll understand

4) NO - I already told you above - The B0026 does NOT set the MIL. You have another problem - check for codes.

Last edited by BlackZ06; 10-20-2007 at 05:59 PM.
Old 10-19-2007, 04:14 PM
  #19  
sks
Instructor
 
sks's Avatar
 
Member Since: Apr 2006
Location: Los Angeles CA
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by BlackZ06
4) NO - I already told you above - The B0026 does NOT set the MIL. You have another problem - check for codes.
Thanks. There is no other code.
Old 10-20-2007, 12:22 PM
  #20  
BlackZ06
Safety Car
 
BlackZ06's Avatar
 
Member Since: Aug 2000
Location: San Rafael CA
Posts: 4,933
Likes: 0
Received 24 Likes on 19 Posts

Default

Originally Posted by sks
Thanks. There is no other code.
The MIL is on and you have no other codes ?? What year is your car ??(you should fill out your profile). How are you displaying the codes ??? Are you ignoring History codes ??? A History code can/will set the MIL in many cases.

Use these instructions and in MANUAL mode display/list EVERY code stored in the car. I find it hard to believe that you don't have at least one or two comms codes stored in the car (Uxxxx) ....

https://www.corvetteforum.com/techti...D=26&TopicID=1

Thread Tools
Search this Thread
Quick Reply: DTC B0026 LF/Driver Frontal Deployment Loop (Single Stage or Stage 1) Open



All times are GMT -4. The time now is 03:09 AM.