Disconnect the battery and still access from passenger door?

[gambe94500]

Hi guys,

So to give a bit of background I'm trying to replace my final stage unit on my 2002 540i. I've read a lot on diverse forums and I'm pretty sure I get the procedure for that, however I'm having some issues with preparing for the job.

I've read that it is preferable to disconnect the battery before working on the electrical system. To do so, it is advised to lock the car, wait for the ~16mins for the car to go from sleep mode to fully shut down and only then disconnect the battery. Great got this. Tried yesterday and after triggering the alarm multiple times I realized I also need to remove the fuse (48). Perfect. Then I realized I couldn't open the passenger door manually, only the driver's.

Should be easy enough then, was planning today to just open both front doors, lock the car, wait for the complete shut down and do the job. Now I'm reading that I can't lock the car with the front doors open...

How am I supposed to do the job with the battery disconnected?? Should I just disconnect the battery without locking/waiting for the shut down?

Thanks in advance!

PS: Sorry if that's already answered somewhere, tried to search but didn't find anything about that specific question.

[ross1]

With ign. off unplug the old one plug in the new one. No need to disconnect the battery for this job.

[gambe94500]

I see, that makes it a lot easier... is there any reason there's no need to disconnect the battery given I'm still interacting with the electrical system? thanks!

[Ed CT]

Un-lock all of the doors, open the trunk, wait for the light to go out, then disconnect the battery without waking the car up (i.e., opening a door, closing the trunk, etc.). No need to have the car locked up to have it go into sleep mode.

As ross1 says, if you're not disconnecting anything else besides the final stage unit, (such as air bags!), no need to discon the battery.

[gambe94500]

Thanks to both of you, was able to replace the FSU without disconnecting the battery and HVAC is back!

For some reason I had a 12-pin E46 (I believe) in there instead of the 39-pin one that's OE.. anyway that's one of my first fixes done.

[crdiscoverer]

FWIW, I've disconnected the battery innumerable times without waiting for the electrical system to go to sleep, never had any issues in almost 20 years of owning the car. In fact, this is the first time I hear that's a thing you have to do.

[StephenVA]

+1^

[sleuth255]

+2^

[theWalkinator]

+3^