Need Help/Suggestions. Navi/Radio Stopped Working

[Mafiok]

I have a 2002 BMW E46 M3 Vert.
I was recommended to this post by my fellow BMW enthusiasts from m3forum.net.


This is my problem:

My Navi/Radio head unit stopped working. When I turn On the car, the “Warning” screen comes on and just stays there. I am not able to press the right knob (navigational button) to confirm, nor am I able to turn on the Radio by pressing the left knob. I am not able to flip open the face plate either.
I checked inside the trunk and there is power to both the Computer and CD Changer. I am able to eject the CD from Navi unit and also the CD changer. When I put the discs in, I can hear it cycling through.
I also tried the fuses, but it didn’t help. I pulled fuse # 7 & 41 out then put it back in but it didn’t help.

Update:
Yesterday i discontected my battery for 2 hours but it didnt help.

Any suggestions? Need HELP!!!!

[Brian-bmw]

That could be caused by a general electrical issue like a bad battery or bad ignition switch.

Is your battery original, or is the hydrometer/sight glass a green dot or a black dot. If you have the black dot, then you may need a new battey. Here is a test you could attempt. Connect the car to a battery charger and then try to operate the radio. If the behavior changes, then it is your battery.

The other possible problem is the ignition switch. This can cause similar symptoms on the E53, E38, and E39. I assume that the E46 would have the same vulnerability and symptomatic behavior.

If it is not power, then you could just have a dead nav computer.

[ccfj1]

Sounds more like an i-bus problem.

e46 Verts are prone to water ingress into the boot mate.

Things to try:

1: disconnect the phone module (if you have one), and try the system.
2: disconnect the cd changer, and try again.
3: disconnect the radio module, you will get no sound but the screen **should** still work.

If still the same reconnect and then...

If you have a mk3/mk4 and TV module, then...

4: disconnect the TV module and try the system, if working TV module Kaput.

Then (if TV module makes no difference).

5: power down the mk3/mk4 (correctly) and then disconnect it and bypass the nav computer by plugging in the blue lead from the nav into the blue plug of the TV.

again, if working Nav module Kaput.

If all this has no effect, then the HU is Kaput (probably).

Testing the components individually narrows down the module that's broken.

Doing the donkey work yourself saves money if you have to take it to a dealer.