Seat removal

[TOMGREEN413]

Sorry, I've tried a search of the forum to check the procedure but nothing found.
Just wondering if l can get away with just unplugging the seat connection once the four bolts are removed or is important to leave it 30 mins after connection at battery has been disconnected ? Many thanks Tom

[Timmyboybunter]

My conclusion was (and would be if doing again), why risk not waiting? 20 minutes for me any time an airbag is involved.

[TOMGREEN413]

So is there a chance that on removing the seats electrical plug it could trigger the air bag ? If so then definitely not worth the risk.

[TOMGREEN413]

Just found the " how to guide section "........so I'm going to loose myself in the various threads for some intensive education

[TheDan]

It wouldn't necessarily trigger the airbag (can happen but I haven't heard of it on here). The main issue is if you unplug the seat connector while there is still some residual power left in the airbag module then it will give you an airbag warning light that isn't very easy to turn off.

Its worth just popping out 20-30 minutes before you do the job and whipping the connectors off the battery then go back inside, have a cup of tea and get all the tools ready.

[Timmyboybunter]

As above - same deal with the main steering wheel airbag and those on the door cards (and the seat belt pretensioners?? Memory fading).

In this case, it's an easy way to lessen any risk just by sitting tight for a short period of time, so why gamble. You'd be gutted to cause any additional inconvenience just for the sake of saving 20 minutes (those airbag lights are either dealer or slightly more expensive code reader/laptop to get rid of).

[TOMGREEN413]

[smorris_12]

I see this "disconnect battery for 30 mins" thing for everything from airbags to "resetting" ECUs and I do wonder where it started. I'm only an electronics engineer, but any sort of module will stay alive for a period measured in seconds at best.

The capacitors that the circuitry might run from are there to stop noise and ripple in the power free and nothing else. There simply isn't a design requirement for anything to stay going post power removal apart from the odd real time clock. In modern cars where there might be telematics that want to work post accident them they'd probably fit a battery.

As for airbags, the designers are well aware that explosives going off in the face of mechanics is a Bad Thing so will have designed them to only go off under very specific circumstances.

A good example of this is any airbag or pre-tensioner connector. Look closely at the socket on the explosive and you'll see a metal bar specifically there to short out the detonator pins as soon as the plug is removed. The short circuit means no current can follow through the trigger so no boom.

Finally, re BMW, as long as you don't turn the ignition on while one of the explosives is disconnected, you won't get the dash light. And they certainly won't start going off in your face if you do!

(Oh, and one fireworks night I set off a couple of pre-tensioners and an airbag for entertainment value. The former go off like fire crackers. The latter makes you want to go back to driving something from before they started fitting them. They are *loud*.

[grannyknot]

Removing the seats from a coupe is not a lot of fun, I would advise you to cover the threshold with cardboard, very easy to scratch a number of things on the way out.

[Zedebee]

A very sensible and informed response from Scott .
I’ve disconnected the battery and moved the seats more or less straight away on several Z4s with no issues. On the odd occasion that I have forgotten to disconnect the battery, I have got the airbag light which has been easy to clear with a Creator 310+.

I echo Grannyknot. It’s a hell of a lot more difficult to get seats in and out of a coupe. An extra pair of hands helping from the adjacent seat is definitely worthwhile

[TOMGREEN413]

Sounds like a bundle of fun........ can't wait.............well maybe I will as a holiday beckons shortly so my job list will be put on hold till I return.

[DMike]

OP has an e89, so read with a pinch of salt…Having removed my e85 seats (electric) numerous times, my tip would be to remove first aid kit, roof down, seat back and front to undo the bolts/nuts; then mid position and make the seat as small as possible (all the way down, seat back up); then disconnect battery and finally the connector. Easier to lift out as a smaller package. Never managed to scratch anything, but putting old socks on the ends of the rails, which are probably the only parts that could seriously cause scratches, could help, if in doubt.

Had the airbag light a couple of times, probably from skipping the wait after disconnecting the battery. I have had INPA, so not a big deal.

[skelters]

Don't forget about the clip for the seatbelt guide thing.

It'll probably be stuck but a bit of force and it'll unclip.

The seats are coming out for what reason?

[Zedebee]

OP has an e89, so read with a pinch of salt…

OP also has a Montego Blue Coupe, so I’m assuming we’re talking about that.

[DMike]

OP has an e89, so read with a pinch of salt…

OP also has a Montego Blue Coupe, so I’m assuming we’re talking about that.

Oh, missed that. Need new glasses. Well, then skip at least the open roof part.