Airbag Faults after seat and seat belt swap (997.1TT)

[TypeRx]

Hi all:

I'm obviously new to this forum -- looks like some great technical discussion! Okay, I came across this site trying to address an issue I am experiencing with my new-to-me 2007 911 Turbo. 

 

Situation:

• Bought the car a couple months ago (45K miles) and it had full leather adaptive sport seats with heat/memory as well as deviated seat belts. 
• I knew I wanted to change the seat belts throughout the car to standard black but didn't want to pay for brand new ones and was uncertain about re-webbed ones from Maxspeed, etc. So, I sourced used ones.
• Rear belts were from another forum member and had a clear history.
• Front belts were from LA Dismantlers, so presumably from a donor car
• Prior to replacing the belts, I acquired a set of of leather/alacanta insert adaptive sport seats with heat memory from the same forum member as the rear seat belts. The seats came from a 2009 TT. The seats were complete with buckles.
• I installed seats and belts after disconnecting the battery for 20+ minutes. All connectors appeared to be well seated. 
• Upon reconnecting the battery and starting my car, I received a variety of faults but all cleared within <1 mile of driving and a restart. However, the airbag light remained illuminated. 
• I since sold my deviated belts so cannot test a known good pair. I still have my original seats (sitting in my living room). 

Where I am at today:

• I used a Durametric Enthusiast to further investigate the airbag light and came up with 2 codes:

1. 8039 - Driver's belt tensioner below lower limit
2. 803A - Passenger's belt tensioner below lower limit

• I attempted to clear the codes but they continue to pop right back up. Airbag light remains illuminated.
• I looked under the seats to make sure the plugs are well seated and they appear so. I will completely unplug and plug back in this weekend just in case.
• I am pretty certain I properly re-inserted the tensioner plugs into the front belts but will need to pull panels off and recheck this weekend

Questions I have:

• Are these codes likely emanating from the seat belts or under-seat wiring? Is it possible they are coming from the buckles?
• Is this the typical fault seen after the tensioners have been been used already? Since I received the belts from LA dismantlers, it is possible the tensioners are now DOA. While LA Dismantlers inspects the seat belts prior to sale, it isn't clear to me if they test the tensioners to still make sure they are good before reselling.
• I have seen online that you can test tensioners by measuring resistance across the terminals on the units using a standard multimeter. A steady 2-3 ohms is good, fluctuating lower or higher numbers means the tensioners are dead. Does this procedure work for Porsche units (the seatbelts will be unplugged/no power, of course)?
• Durametric has told me the unit will clear the code no problem as long as the issue that triggered the fault is fixed. I've read conflicting advice on other sites, saying that a dealer PIWIS reset is required. Which one is true?
• Is there a comprehensive list of Porsche 997 OBD2 airbag fault codes available? I'd like to scan through them to better understand how to isolate my 2 errors to the seatbelts, seats, or buckles.

Next steps:

• I am going to ensure wiring for the seats and seat belt tensioners is fully seated. I'll double check grounds and other wiring nearby as well. I'll also try to test resistance within the tensioners as mentioned above.
• LA Dismantlers offered to send me another set of front belts, but I don't want to replace them just yet...

1. I don't know for sure that the belts are bad....

Wow, sorry for the long post but hopefully everything is crystal clear. Now I hope one of you smart folks can help me answer some of the questions I raised. 

 

TIA!

[JFP in PA]

Welcome to RennTech :welcome:

I get nervous when you start swapping or mixing seatbelt components across different model years (your 2009 buckles and 2007 belts) as Porsche has updated these units over the years and I do not know about how compatible different components are.  Are you reusing the car's original tensioners, or did they come from the breaker's yard?

 

The Durametric system will clear these codes once the issue is fixed, but finding out where the issue lies is going to be the problem.

 

As for lists of codes for the 997, Porsche used to publish such information (under copyright) for the older cars, but when all electronic in the mid 2000's and they are only legitimately available on their TSI subscription system.

[Hilux2400]

When front seats are removed from a 996 is there a safe waiting period, after the ignition is switched off, to avoid air bag operation?  I know the under seat connector remains live after the ignition is switched off so that the seat controls can be operated. 

[TypeRx]

Thanks for the response. Here is the situation:

 

Front seat belts: Don't know year, just know they are for the 997 Carrera. Part numbers confirmed to be identical for my 2007 911 per the Porsche PET Manual. Left: 99780303300 A23 , Right: 99780303402 A23 

Buckles: From a 2009 911 Turbo

Seats: From a 2009 911 Turbo

Rear belts: From a 2009 911 Turbo (but who cares, no electrical connection to these)

 

When you ask if I am using my car's original tensioners...I guess the answer is no. The front belts are integrated with the pre-tensioners, and those are from the dismantler. The seats, which have wiring that communicates with the pre-tensioners, are not from my car either. 

Haha, through this I've realized that I have just created a Frankenstein car. Oh boy....
 

 

[TypeRx]

When front seats are removed from a 996 is there a safe waiting period, after the ignition is switched off, to avoid air bag operation?  I know the under seat connector remains live after the ignition is switched off so that the seat controls can be operated. 

 

I've *heard* from multiple people to wait 20 minutes as the SRS system may still be energized shortly after battery power is disconnected. I think this applies/is good practice with all cars with such systems (basically anything after what..1993?) so better safe than sorry. 

[JFP in PA]

Thanks for the response. Here is the situation:

 

Front seat belts: Don't know year, just know they are for the 997 Carrera. Part numbers confirmed to be identical for my 2007 911 per the Porsche PET Manual. Left: 99780303300 A23 , Right: 99780303402 A23 

Buckles: From a 2009 911 Turbo

Seats: From a 2009 911 Turbo

Rear belts: From a 2009 911 Turbo (but who cares, no electrical connection to these)

 

When you ask if I am using my car's original tensioners...I guess the answer is no. The front belts are integrated with the pre-tensioners, and those are from the dismantler. The seats, which have wiring that communicates with the pre-tensioners, are not from my car either. 

Haha, through this I've realized that I have just created a Frankenstein car. Oh boy....

 

 

 

If memory serves, the pre-tensioners have to be coded to the car, which is really setting the system controller to recognize them.  This could be the source of your issue, and I believe will require the use of a PIWIS to accomplish.

[TypeRx]

 

Thanks for the response. Here is the situation:

 

Front seat belts: Don't know year, just know they are for the 997 Carrera. Part numbers confirmed to be identical for my 2007 911 per the Porsche PET Manual. Left: 99780303300 A23 , Right: 99780303402 A23 

Buckles: From a 2009 911 Turbo

Seats: From a 2009 911 Turbo

Rear belts: From a 2009 911 Turbo (but who cares, no electrical connection to these)

 

When you ask if I am using my car's original tensioners...I guess the answer is no. The front belts are integrated with the pre-tensioners, and those are from the dismantler. The seats, which have wiring that communicates with the pre-tensioners, are not from my car either. 

Haha, through this I've realized that I have just created a Frankenstein car. Oh boy....

 

 

 

If memory serves, the pre-tensioners have to be coded to the car, which is really setting the system controller to recognize them.  This could be the source of your issue, and I believe will require the use of a PIWIS to accomplish.

 

 

If that is the case...now we are getting somewhere. I still want to test the seat belts themselves to see if the ignitors are dead. But now I am nervous because I've seen people cautioning not to do it since a multimeter applies a very small voltage to the unit and therefore carries the risk of igniting them! But at the same time, there are youtube videos and the like of people doing it without issue. Argh. Maybe I just need to get my car to an Indy with PIWIS and see what happens....