Occasional COMAND pop problem
#1
Occasional COMAND pop problem
Hi,
I have a strange issue with the COMAND unit on my 2004 wagon. The symptoms are this: if I'm listening to the aux input every 15 minutes or so there is a pop noise on the speakers and the phone cradle with BTUM loses connection. If I have the nav screen on, it resets for a moment as it reconnects to the DVD drive.
If I disable bluetooth on my phone and remove the BTUM, the system still makes the pop noise and does the reset. It's a very strange reset as the unit retains power and the display stays up, but I lose aux audio for about 2-3 seconds and the phone cradle resets. Any idea what's going on? A loose fuse or connector? A bad module?
As always, advice is hugely appreciated.
-n.
I have a strange issue with the COMAND unit on my 2004 wagon. The symptoms are this: if I'm listening to the aux input every 15 minutes or so there is a pop noise on the speakers and the phone cradle with BTUM loses connection. If I have the nav screen on, it resets for a moment as it reconnects to the DVD drive.
If I disable bluetooth on my phone and remove the BTUM, the system still makes the pop noise and does the reset. It's a very strange reset as the unit retains power and the display stays up, but I lose aux audio for about 2-3 seconds and the phone cradle resets. Any idea what's going on? A loose fuse or connector? A bad module?
As always, advice is hugely appreciated.
-n.
#3
Maybe another pointer?
#4
It sounds like you are experiencing random MOST bus resets. MOST is the fiber-optic data bus that all of the sound and navigation entertainment talk to each other on. It can be caused by a misbehaving component or some physical problem with the fiber.
There are two ways I would start to diagnose:
- Find someone with STAR tool to look at the fault codes and error logs
or
- Carefully inspect all of the fiber optic connections and components. If all physically looks well, you will have to disconnect each component and loop back it's fiber optic cabling. Once the problem goes away, you have found the faulty component.
There are two ways I would start to diagnose:
- Find someone with STAR tool to look at the fault codes and error logs
or
- Carefully inspect all of the fiber optic connections and components. If all physically looks well, you will have to disconnect each component and loop back it's fiber optic cabling. Once the problem goes away, you have found the faulty component.
#6
While I really dislike giving advice that is not based on experience and fact....I am going to guess that there is some sort of watchdog that is causing the reset. This watchdog is an electronic timer that must be periodically "fed" by software. If the unit's CPU freezes, the watchdog isn't fed, and it forces the unit to reset.