550 passenger airbag cover

If you search this forum, you will see complete instructions on how to do that. It is not onerous.

 

+1 to Frank's comment. It's a simple weekend project and fairly gratifying. Just be sure when you reinstall the airbag you are certain to plug the airbag back in (the yellow cable) before you energize the system otherwise you can have all sorts of problems, some very expensive. At the least it'll throw an SRS code (evidenced by the airbag light not going off after the usual self-check) that requires an SD or Leonardo to clear (e.g. not like the same mistake in a 360). Plus you'll need a tech that *knows how* to use the computer since, apparently, not all do. Ask me how I know this expensive lesson...

 

Not sure what you mean by "Is it enough to unplug the battery.". To do a proper job you really should remove the airbag and that requires disconnecting it. That said, I would also unplug the battery when doing anything with the airbags as they are an explosive and I, for one, greatly respect that. In fact, I go perhaps a bit overboard and after turning off the battery (necessitating a drive cycle later, but those are fun...) I let the car sit for a couple days to let the SRS capacitors unload before getting into the yellow cables. Experts have told me this is "excess respect" but, with airbags (again, explosives), I don't know how this is possible. If I was in a hurry I'd just let a good shop do it. They have a professional understanding of when and where to apply caution. I just apply it everywhere (when working on the 550) and enjoy myself.

 

First of all, thanks for your input.

Sorry, I don't understand what you mean with "necessitating a drive cycle later, but those are fun..."

**When you disconnect the battery ideally you should run the engine in a specific manner to properly calibrate all the sensors. It takes less than 10 minutes and involves driving several miles. You don't have to do this but it helps in avoiding unnecessary CELs (Check Engine Light warnings). The car will self-calibrate but it takes a lot longer. You can search this forum for the procedure.

With "unplugged the battery", I mean unplug the complete car from the 12V battery power.

**Sure. I assume you are just using the switch by the battery and not disconnecting the leads to the battery itself. The switch is handy and there for a reason as our cars do have a parasitic drain even when sitting (these days, most cars do). In time this will drain the battery and starting a 550 with a low or dead battery is not trivial (e.g., jump starting is ill advised). Battery tenders are a good thing.

Yes, I also have much respect for the airbag's. Can the airbags also explode when the car is completely without battery power?

**Good question. I've heard yes and no, if the battery is disconnected. That said, the bags are fired by potent capacitors in the airbag ECU. Capacitors hold their charge for a period of time even disconnected from the battery. I may be over cautious but with 17 year old Italian wiring I'm disinclined to take any chances with shorting anything (I've had an airbag go off in my face. It is not a recommended experience...).

I hope I understood this correctly and can now dismantle the airbag, since the car is after such a long time without battery power.

**You should have no problem then. Be sure to properly charge the battery before trying to start the car. I suggest you have the battery tested to make sure it's good. DO NOT try to start the car with a low or bad battery as you can cause an array of expensive problems,. Also, a good habit when starting a 550 is to pause the key twist a few seconds before engaging the starter. This allows the airbag capacitors to charge--just wait for OK to come up on the MFD. The OK means the self-diagnostics are complete and you’re good to go. If you just insert and quickly twist the key the electrical surge can (rarely, but it happens) damage the airbag ECU (not good) and throw the SRS code. I gather this is overkill if the car has been run within a few hours but it’s a good habit to get into. This takes only a few seconds and our cars are fast enough to make up the time...

 

Peter550: If you have disconnected power and have the airbag nuts removed you might as well go ahead and pull the airbag all the way out. Just be absolutely certain to plug it back in when you replace the airbag. You will find that the airbag is *much* easier to work on when it's on a work bench (or a granite kitchen counter if your wife is understanding...) with good light, and comfort, than trying to work on it in the car. This is because restretching the existing leather (if that's your plan) requires care and leverage that's hard to come up with while it's in the car. Remember, for it to look right you'll have to wrap the leather around the edges which requires the careful application of contact cement over the lip and that's tough to do when the bag is in the vertical position in the cockpit. Just pull it out, take your time, and enjoy yourself. Your results will likely be better.

 

Well done!