Software engineer requiring assistance…

**IceX** · 01-10-2008, 02:51 PM

Removing the car radio...

I have spoken to one of the expert (audio) consultants for BMW just now.

He mentioned to me that once you remove the radio in the BMW E46 that it will be causing endless trouble.

He said: “The radio is a vital piece in the cars electronics and that once removed it will disturb the “LAN” interface for the cars computer electronics and will result in services to the car will give incorrect readings on the electronics.

Logic tells me that BMW would have thought further than that and would have allowed for the correct readings even if the radio is not connected.

I doubt this will have any impact on my car (BMW 325i E46 - 2001), it might be so for the 2007 or 2008 models (but I highly doubt it)?.

What are your thoughts on this?

**jontz** · 01-10-2008, 07:32 PM

Well, there might be something to it, but I can't give you a difinite yes or no. I know that Cadillacs are crazy integrated, and if you pull the radio in certain models things can go haywire. I guess what I would do is pull the radio out, drive around without it for a couple of days, and if nothing bad happens then go ahead with your carputer install. If something does go haywire, just put the radio back in. No harm, no foul.

**Bugbyte** · 01-10-2008, 08:04 PM

First - I don't own an E46, but knowing how many 325's there are on this forum, I'd be willing to bet that this isn't the case. Check the show off your projects forum and search for your car type. You're almost certain to find that someone has done it and can advise you on it.

**Jistari** · 01-10-2008, 08:05 PM

In the C5 Corvette you will get a "loss of commuication" code in the on board diagnostics when the car starts and the radio doesnt check in on the bus. Not a problem unless you run the onboard diagnostics, you will just see a code in the comm section.
And I'm not sure, but I think you will aslo loose the audible things from the car like door open chimes, keys left in . . .etc.
But it wont affect the driveability.

**IceX** · 01-11-2008, 06:20 AM

Originally Posted by Bugbyte

but knowing how many 325's there are on this forum, I'd be willing to bet that this isn't the case.

You are correct

(my first thought also). I have realized and did find numerious bmw 325's on the forum before I even started with my car project.

As indicated above I might loose sound for doors, keys left, etc. those kind of things does not bother me because I never had them in the first place

I have had the radio removed for a couple of days (due to radio repairs) and driven the car without it and did not find anything not working or faulty but as stated above it might mess with the onboard systems (only for the guys doing a service on the car).

If it is small tedious things that I might possibly lose specific to audio, then I can always make up for it by building my own hardware interfaces and programming it

I am currently setting up my PC, will give your more foto's / details and information / images once I received my bezel!

**IceX** · 01-24-2008, 12:10 PM

I did not receive any connection information with my controller and need to verify connections:

I don't understand why there seems to be two 12v+ and two ground cables?

I also understand the yellow wire is connected to the ignition, but what is the purpose of the blue wire, as there is no text indication or label as to what this line is?

Any assitance would be greatly appreciated... thanks!

**Bugbyte** · 01-24-2008, 04:44 PM

I believe the blue wire signals the amplifier to turn on. It prevents a loud "POP" sound when the computer wakes up. If you don't have an amp, don't worry about it.

There just ARE two of each. I believe it is because the connector type accepts small gauge wires. Hook them both up so you get the same effect as a larger gauge wire. Carries more juice and reduces heat than if you hooked up a single wire.

**IceX** · 01-25-2008, 01:36 AM

Originally Posted by Bugbyte

I believe the blue wire signals the amplifier to turn on. It prevents a loud "POP" sound when the computer wakes up. If you don't have an amp, don't worry about it.

Thanks for the reply. Yes I do have an amp... so I suppose the blue wire is used as the power out to the amp?

Meaning I only earth the amp and then draw it's power from the blue wire or would I still need to draw direct power from the battery?

My understanding is that the blue wire is acting like a bridge/relay to switch power once the PC is turned on, but that the blue wire is the actual power source for the amp then?

**Jistari** · 01-27-2008, 05:46 PM

Someone will chime in but in the interim, no I doubt that you will be powering the amp on the blue line, the amp should have a direct power line and an input to tell it to turn on when it see's voltage on the blue line.

**Bugbyte** · 01-27-2008, 08:14 PM

Originally Posted by IceX

Thanks for the reply. Yes I do have an amp... so I suppose the blue wire is used as the power out to the amp?

Meaning I only earth the amp and then draw it's power from the blue wire or would I still need to draw direct power from the battery?

NO! The blue line only provides a very low power signal to the amplifier to turn on. The amp would get its power from a separate line.

Most amps come with a wire that gets connected to a 'signal' wire such as the accessory line that switches on when you start the car. The blue line delays that signal and keeps the amplifier from switching on too soon. Otherwise, you get a very loud "POP!" if the amp switches on BEFORE the computer comes on.

On your amplifier, it is probably called something like "remote on".

From the Carnetix site, you can see that the blue line performs a remote trigger function.