Air Bag Scan Codes

[bigbipper]

Hello All,

The battery died a few weeks back in my 2005 Suburban. I jumped the battery and then it threw a "Service Airbag" message and light. I scanned the codes and I got BOTH a B0100 and a B0103.

 

I see that they are for both front sensors. I mean...what are the chances that BOTH just went bad?

 

Any suggestions for I replace both?

 

Thanks so much, guys...and gals.

 

 

[bigbipper]

Clear them and see if they return. Also make sure your electrical system is in shape, i.e. battery, alternator, cables, grounds

Thanks much.

I did clear them and BOOM...came right back.

 

Battery and alternators are strong. Have read a lot about "Unplugging" the sensors, then plugging them back in. Sounds like that could work on 1 sensor, but the dual codes really make make think something else may be happening.

[bigbipper]

Without even knowing what the codes mean, my best guess is they have something like low voltage in the meaning. When the battery failed, it supplied a low voltage. As suggested above, replace battery, have starting/charging system checked, reset the codes, or have a shop do it, and drive. If codes come back, then look into it.

Actually, correction on the battery. I did mentioned that it was drained from playing the radio too long. However, the battery was brand new prior to this bonehead mistake; maybe 2 months old.

 

Wouldn't it charge itself back up to proper specs?

[Doug_Scott]

Your charging system appears to be ok based on the voltages you are seeing. About all you can really do is verify that all connections in the air bag system are clean and tight.

 

Boosting a vehicle that has a completely dead battery can create issues with some of the electronics. Personally, I have never had any issues, or seen any issues first hand, with damage caused by either incorrect boosting procedure or by the dead battery causing a surge. To me, the only way I can imagine any damage being done by boosting a dead battery would be if the key was not in the off position on the dead battery vehicle when cables were connected with the boosting car running. If key was off, I don't see how any circuits that are inactive with key off could be damaged. This is based on how I troubleshoot electrical issues.

 

Is it only the air bag circuit that you are trying to correct? Does your truck have a switch for disabling the passenger side air bag? Have you tried clearing codes, and disabling passenger side air bag, and then see if both codes come back.

[txab]

I'd still check electrical thoroughly. These trucks are pretty picky about power supplies and wiring. Disconnecting and reconnecting the sensors can't hurt

[bigbipper]

Thanks for your input, guys. I pulled the plugs on both sensors, reconnected, cleared codes...but they promply returned. I am not convinced that both sensors are bad. The focus has now fully shifted on the electrical and charging system.

[bigbipper]

Your charging system appears to be ok based on the voltages you are seeing. About all you can really do is verify that all connections in the air bag system are clean and tight.

 

Boosting a vehicle that has a completely dead battery can create issues with some of the electronics. Personally, I have never had any issues, or seen any issues first hand, with damage caused by either incorrect boosting procedure or by the dead battery causing a surge. To me, the only way I can imagine any damage being done by boosting a dead battery would be if the key was not in the off position on the dead battery vehicle when cables were connected with the boosting car running. If key was off, I don't see how any circuits that are inactive with key off could be damaged. This is based on how I troubleshoot electrical issues.

 

Is it only the air bag circuit that you are trying to correct? Does your truck have a switch for disabling the passenger side air bag? Have you tried clearing codes, and disabling passenger side air bag, and then see if both codes come back.

Doug, as always, thanks for your reply and concern.

At this point the only circuit that appears to be compromised is that of the air bag.

 

I have not tried what you suggested, but will try this evening.

[txab]

Clear them and see if they return. Also make sure your electrical system is in shape, i.e. battery, alternator, cables, grounds

[gmtech4]

It's a hard code, it has to be gone thru by a technician not a truck owner

[Doug_Scott]

Without even knowing what the codes mean, my best guess is they have something like low voltage in the meaning. When the battery failed, it supplied a low voltage. As suggested above, replace battery, have starting/charging system checked, reset the codes, or have a shop do it, and drive. If codes come back, then look into it.

[bigbipper]

Ok, so I noticed that this is where my Battery reading is currently living while the truck is running. Concerns?

 

[Doug_Scott]

Actually, correction on the battery. I did mentioned that it was drained from playing the radio too long. However, the battery was brand new prior to this bonehead mistake; maybe 2 months old.

 

Wouldn't it charge itself back up to proper specs?

 

\Not sure where you mentioned the part about the radio, it was not in this thread. Same for the part about resetting the codes, and they came right back. When I post a question on multiple sites, I compose the post in notepad, then paste it on each site. That way all forums get the exact same post, and I don't forget to include something on one forum.

 

If the charging system is working correctly it may be able to bring the battery back. I say "may" because not all batteries will come back from being run flat. But that is why new ones come with warranties. Worst thing you can ever do when diagnosing something is to assume it must be working, its new. If that was the case 100% of the time, the part would not require a warranty of any kind.

 

Follow the wires back from the sensors and unplug, inspect, clean and reconnect all connectors in those circuits. That is about the limit for the backyard mechanic on troubleshooting air bag circuits. Personally I would not take anyone's advice beyond this point on servicing the air bag circuit, and I am a licenced mechanic who started down this road in 1977. Come to think of it, I just recalled reading a popular mechanics magazine article that talked about this way in the future safety thing call an air bag.

[gmtech4]

^^^^^^^^^^^ yup !!!

[txab]

Doesn't look like your "battery and alternator are strong". Get them checked out, along with cables and grounds

[bigbipper]

Try using a quality volt meter directly on the battery, and also check output at the big wire on alternator. Factory gauges are not 100% correct. Some are closer than others. Sort of like the fuel gauge, and temp gauge. Most gauges depend upon good supply to the gauge and good ground on way out.

 

When you start the engine cold, how long before gauge hits the final voltage?

This truck has not got much work since I last posted here, but here comes winter and an over due inspection. Airbag warning light remains on with a b0100 and b0103

 

A voltometer has shown the following readings:

 

Battery (ignition off): 12.9v

Battery (ignition on): 14.4

Alternator (igintion on, red lug and grounded): 14.8

 

I have to assume that means the charging system is in proper order?

 

The following troubleshooting has been completed:

 

• Clear codes (only to come back)
• Remove Negative cable for an hour
• Unplugged/Plugged air bag fuse
• Unplugged/Plugged both front sensors

The one thing I am yet to try is a new battery, but as mentioned, this was a brand new batter that I drained accidentally and had to jump. After the jump is when the Airbag light and codes were thrown.

 

I'm guessing my next stop is to my mechanic.

 

Thanks to all who chimed in. Appreciate your time and efforts.

[Doug_Scott]

Try using a quality volt meter directly on the battery, and also check output at the big wire on alternator. Factory gauges are not 100% correct. Some are closer than others. Sort of like the fuel gauge, and temp gauge. Most gauges depend upon good supply to the gauge and good ground on way out.

 

When you start the engine cold, how long before gauge hits the final voltage?