SRS airbag light on, communication issue? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

2003 Boxster base. All seems to be standard. No SRS issues initially. Took the car to be painted (no repairs - except small dents/rings, just pain job - nothing major body wise). Picked the car up - airbag light on. I thought airbag was disconnected with battery on. No biggie. Durametric will clear it. It did not. Took it to the dealer. They say - communication problem. No VIN in SRS module. They hassle with it, no resolution. I pay for time. $$$ A side story - I lost horn. Turns out the clock spring is damaged (it must have been wrongly assembled when I was replacing the turn signal stalk and cracked - it was bent in one place and over time it cracked). I replaced it with a working one. Horn is back. All seem to be fine. So far - resolution is to order a new SRS module. Factory new. That is nearly 2 thousand dollars. Anyone here could help? Further questions. If the module is faulty, can I get a used one (same part number)? Is it true it must be VIN coded? Can dealer, or someone else, code a used module? Any other ideas?

Yes, the airbag module has to be coded to the car, which requires a PIWIS system. A used one MAY be able to be coded, but that is not a guarantee.

Quotes source post: 650024

JFP... is that for specific years? I swapped out my 4-spoke for a 3-spoke on my 98, having disconnected the battery beforehand. No lights, No hiccups. Was I lucky? The reason I ask is because when I installed the 3-spoke... I did so a couple of splines off... rendering the steering wheel not perfectly straight when driving. If I remove and reinstall the steering wheel... should I be concerned about needing to have the SRS coded? Thank you.

Quotes source post: 650041

Changing a air bag, or steering wheel, does not impact the air bag control module, but the control module itself MUST be coded to the car, which requires the PIWIS.

This doesn't make any sense to me. The SRS is a physical box hard mounted to the center tunnel under the center console. First, unless the entire unit has gone bad (water exposure?), it wouldn't just lose it's coding. That's not how rom works. Second, what does a paint job have anything to do with that system? Or is this just a coincidence? It may help to find someone with a piwis and do the diagnostic yourself. I have no idea what the procedure is for programming the airbag system but clearing the light is quite easy. Sent from my SM-N976V using Tapatalk

Quotes source post: 650096

We have seen this a couple of times when the system has been messed with, for some reason the module loses its coding to the car. Exactly why is not known, but time in the body shops seems to be the common denominator, and as the body shop will nearly always claim innocence, we have not figured out what they did wrong.

I thought, I would update it here. After reading some posts, I decided to take the risk and swap the modules. Since I was getting a long list of errors (all aribags) and communication along with voltage, it meant the module is shut. Once of the codes was 195 I think (I can verify later), but for sure it was over 100, what means the module is bad. I looked up on the eBay donor from similar car - another Boxster, 2002, S version. Close enough to mine - 2003 base. I disconnected the battery, removed the module using pliers, and put the new one in. Connected the battery and carefully turned the ignition on. Nothing exploded, so I plugged in Durametric. The 100 codes are gone, the other codes cleared - communication is OK. The only code I have now is 73 for the airbag deactivation - child seat. I will get to it later to see if the buckle is connected and works. So yes, it can be done.

Great, thanks for reporting back! Edit: I studied Chapter 69 53 19 in POSES, there is no programming mentioned when swapping this control but it sday the new module must be "locked". Whatever this means...could be obolete when a used one is used. Found this for the "lock". And this might be useful information for the child set issue.

Perhaps a little background may help. Porsche uses the same control module in multiple vehicles, some of which have safety systems that the Boxster does not, like the 996 cabriolets, which has an "anti-rollover" system that only deploys during a flip. In order for these systems to deploy correctly, the module has to know what systems are available to it, which is what the "locking" sequence does. If you take a use module from one car, say a Boxster, and install in into another vehicle that has the exact same safety systems, it will most likely work. But if you took one from a Boxster, and put it in a 996 cabriolet, you will have problems. And if you took a brand-new module out of the box and put it in any car without going thru the locking procedure, you will encounter problems because it simply does not know what type of systems it is dealing with.

Thank you very much for the insight; this is very important information!