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Subject: Troubleshooting blank nav screen and radio shut off Author: Brian (moderator) : member since January, 2005 : 8586 posts Posted on: 2009-03-27 06:37:40

I have seen a lot of posts lately about cars with the problem that the navigation screen is blank and the radio shuts off after a couple minutes. So, I thought that I would start a quick thread to help troubleshoot it and explain why those two problems are related. This specifically applies to the E38 7 Series, E39 5 Series, and E53 X5 with DSP.

When you have a car with navigation and DSP, and you are getting these two symptoms, it means that you have a bad navigation computer. You need to replace the nav computer (or TV module, if you car is equipped with TV instead of navigation.)

Why this is the case…

In cars with navigation, the navigation computer is the central control for all of the navigation, audio, and visual components. The screen is just a dumb display, much like a monitor for a computer. There are no functions inherently in the screen component itself. Therefore, nav computer is the device that runs the screen. When the screen is blank, the problem could be one of two things: a bad screen or a bad nav computer. However, there is a key relationship between the nav computer and the DSP amplifier.

The DSP amplifier depends on the navigation computer for its control interface. Remember that “DSP” is one of the options on the main menu? The DSP scans the car’s I-Bus network to make sure that all of the other components it interacts with are working (radio and nav computer). If the navigation computer does not respond to the DSP amp’s network communications, then the DSP amp will determine that something in the car is broken, and the amp will shut itself down after a couple of minutes. This is why the radio shuts off after a couple of minutes when you have a bad nav computer.

• Troubleshooting blank nav screen and radio shut off - Brian 2009-03-27 06:37:40 (2920 views)
  • Re: Troubleshooting blank nav screen and radio shut off - raysbiz98 2009-11-10 00:45:56 (32 views)
  • Re: Troubleshooting blank nav screen and radio shut off - riboater 2009-10-25 13:06:14 (84 views)
  • Re: Troubleshooting blank nav screen and radio shut off - plauemd 2009-07-11 04:36:31 (404 views)
  • Re: Troubleshooting blank nav screen and radio shut off - bteeley 2009-06-13 22:30:27 (364 views)
  • Re: Troubleshooting blank nav screen and radio shut off - neilevans 2009-05-07 19:22:39 (496 views)
    • Re: Troubleshooting blank nav screen and radio shut off - fwalton 2009-05-11 23:08:50 (451 views)
      • Yes, it is an easy plug-and-play replacement - Brian 2009-05-12 06:58:26 (515 views)
        • Re: Yes, it is an easy plug-and-play replacement - bteeley 2009-07-01 14:34:30 (257 views)
        • Re: Yes, it is an easy plug-and-play replacement - fwalton 2009-05-17 18:41:07 (324 views)
          • Here are a couple resources... (url) - Brian 2009-05-17 20:40:13 (547 views)
            • Re: Here are a couple resources... - fwalton 2009-05-17 22:19:55 (247 views)
    • Check the blue plug that should be connected to your TV module - Brian 2009-05-07 21:04:36 (361 views)
      • Re: Check the blue plug that should be connected to your TV module - neilevans 2009-05-08 04:09:08 (243 views)
        • Re: Check the blue plug that should be connected to your TV module - neilevans 2009-06-08 21:20:39 (182 views)
  • DId you get this resolved? - pietern740il 2009-04-22 20:55:05 (333 views)
  • Remember, it can also be a simple FUSE. Check them first - Trunk Bank. (nt) - uSa4148 2009-04-01 22:55:13 (552 views)
    • Always good advice to check the fuses first - Brian 2009-04-02 07:26:36 (391 views)
  • Re: Troubleshooting blank nav screen and radio shut off - viperian86 2009-03-31 18:49:20 (462 views)
    • Re: Troubleshooting blank nav screen and radio shut off - dccinc 2009-04-21 12:49:05 (374 views)
    • According to BMW TIS, the firmware corrupt so it's not components. (nt) - bmw635 2009-04-01 00:32:30 (519 views)
      • We will wait to see how mels7 makes out sending his unit to Germany. Maybe - Roy In GA 2009-04-01 16:18:08 (350 views)
  • Re: Troubleshooting blank nav screen and radio shut off - ephillips 2009-03-29 23:50:03 (492 views)
  • word up! (nt) - rex120 2009-03-29 16:10:23 (405 views)