Radio works without the key.

[Santaclaus4]

I have two 2003 540i's and I noticed yesterday that on my project 540i (Pea spelled with two e's) that it's non DSP radio will work even though the ignition key hasn't been any where near it for more than a week. My regular 540i (Princess) has DSP and it's radio won't turn on unless the key is turned to the first position (formerly known as the ACC position). Is that normal?

[TiesTorN]

no. do you have phone in your car?

[Twistytee]

Yes it’s normal for non DSP. Mine does this too and will automatically shut off after a certain time interval to prevent a low battery situation.

[Santaclaus4]

no. do you have phone in your car?

No phone has ever been installed.

Yes it’s normal for non DSP. Mine does this too and will automatically shut off after a certain time interval to prevent a low battery situation.

What do you mean by "certain time interval"? I understand the whole "going to sleep" after 16 minutes but my project car hasn't even had the key near it for a week.

[TiesTorN]

I had a similar situation where my radio module couldn't shut off itself. turned out my phone module which is on the same KBUS line went kaput and interrupting the communication between nav screen and radio module.

yours seems like a different problem but it should be similar. your KBUS module might be dead, radio module may not be getting "turn off" signal.

[Twistytee]

No phone has ever been installed.



What do you mean by "certain time interval"? I understand the whole "going to sleep" after 16 minutes but my project car hasn't even had the key near it for a week.

Starting 9/00, the new business CD radios with the e53 designation can be turned on without the KL R. They should turn off after the 16 min sleep interval but you can awake them again my pushing the volume knob.

See link below for an excerpt from Bimmerboards on the
https://xoutpost.com/bmw-sav-forums/...ed-itself.html

[Santaclaus4]

That was a very helpful link. Thanks for posting it.
It makes much more sense now.
After all these years, I'm still learning stuff about these cars. It's friggin' awesome.