Bose MOST issues
04-04-2022, 10:46 AM
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Bose MOST issues
I recently bought a 2004 996 Turbo with a PCM 2.0 unit. Unfortunately, there is no sound through the dreaded Bose MOST system. The E6/E6/Radio fuses are all fine. I looked at the stock amplifier and I noticed a little corrosion on the big rectangular male connector. I replaced the amplifier with a known working unit and also bypassed the cd changer with no change.
There is a faint static sound through the speakers. The PCM 2.0 unit functions fine even though the system has no sound. When the PCM unit has power, you can see a red laser emitting from the MOST plug when it is removed. I can also see a red laser coming out of the amplifier and CD changer MOST plugs when they are individually removed and the fiber link is broken. I cannot connect to any PCM modules that populate in my PIWIS III. The PCM unit will flash a service message for a few seconds and then it gives a communication timeout code. It could be my PIWIS – although I can connect to other modules without an issue. Before I bypassed the cd changer, it would tell me that the changer was unavailable when I selected the button. The CD changer itself does not have a magazine in it so I did not know if that is a normal message to display if there is nothing for the changer to read. It also tells me that the navigation is unavailable when I select the button as well. I am not sure if I have to insert the disc for it to work.
Any ideas on what the issue could be? I am leaning towards trying another PCM 2.0 radio. Maybe I can grab one at the Hershey swap meet. In the meantime, does anyone know how the MOST link is daisy chained? Does it go Radio -> Amp -> CD Changer -> Radio? Looking at a picture of an ebay PCM 2.0 navigation module, it does not look like it has a MOST connection based off the plugs on the back of the unit. I do not think my car has a telephone module, as there is nothing under the passenger side seat. Am I missing anything?
There is a faint static sound through the speakers. The PCM 2.0 unit functions fine even though the system has no sound. When the PCM unit has power, you can see a red laser emitting from the MOST plug when it is removed. I can also see a red laser coming out of the amplifier and CD changer MOST plugs when they are individually removed and the fiber link is broken. I cannot connect to any PCM modules that populate in my PIWIS III. The PCM unit will flash a service message for a few seconds and then it gives a communication timeout code. It could be my PIWIS – although I can connect to other modules without an issue. Before I bypassed the cd changer, it would tell me that the changer was unavailable when I selected the button. The CD changer itself does not have a magazine in it so I did not know if that is a normal message to display if there is nothing for the changer to read. It also tells me that the navigation is unavailable when I select the button as well. I am not sure if I have to insert the disc for it to work.
Any ideas on what the issue could be? I am leaning towards trying another PCM 2.0 radio. Maybe I can grab one at the Hershey swap meet. In the meantime, does anyone know how the MOST link is daisy chained? Does it go Radio -> Amp -> CD Changer -> Radio? Looking at a picture of an ebay PCM 2.0 navigation module, it does not look like it has a MOST connection based off the plugs on the back of the unit. I do not think my car has a telephone module, as there is nothing under the passenger side seat. Am I missing anything?
Last edited by JustinS; 04-04-2022 at 10:47 AM.
04-04-2022, 11:13 AM
#2
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I recently bought a 2004 996 Turbo with a PCM 2.0 unit. Unfortunately, there is no sound through the dreaded Bose MOST system. The E6/E6/Radio fuses are all fine. I looked at the stock amplifier and I noticed a little corrosion on the big rectangular male connector. I replaced the amplifier with a known working unit and also bypassed the cd changer with no change.
There is a faint static sound through the speakers. The PCM 2.0 unit functions fine even though the system has no sound. When the PCM unit has power, you can see a red laser emitting from the MOST plug when it is removed. I can also see a red laser coming out of the amplifier and CD changer MOST plugs when they are individually removed and the fiber link is broken. I cannot connect to any PCM modules that populate in my PIWIS III. The PCM unit will flash a service message for a few seconds and then it gives a communication timeout code. It could be my PIWIS – although I can connect to other modules without an issue. Before I bypassed the cd changer, it would tell me that the changer was unavailable when I selected the button. The CD changer itself does not have a magazine in it so I did not know if that is a normal message to display if there is nothing for the changer to read. It also tells me that the navigation is unavailable when I select the button as well. I am not sure if I have to insert the disc for it to work.
Any ideas on what the issue could be? I am leaning towards trying another PCM 2.0 radio. Maybe I can grab one at the Hershey swap meet. In the meantime, does anyone know how the MOST link is daisy chained? Does it go Radio -> Amp -> CD Changer -> Radio? Looking at a picture of an ebay PCM 2.0 navigation module, it does not look like it has a MOST connection based off the plugs on the back of the unit. I do not think my car has a telephone module, as there is nothing under the passenger side seat. Am I missing anything?
There is a faint static sound through the speakers. The PCM 2.0 unit functions fine even though the system has no sound. When the PCM unit has power, you can see a red laser emitting from the MOST plug when it is removed. I can also see a red laser coming out of the amplifier and CD changer MOST plugs when they are individually removed and the fiber link is broken. I cannot connect to any PCM modules that populate in my PIWIS III. The PCM unit will flash a service message for a few seconds and then it gives a communication timeout code. It could be my PIWIS – although I can connect to other modules without an issue. Before I bypassed the cd changer, it would tell me that the changer was unavailable when I selected the button. The CD changer itself does not have a magazine in it so I did not know if that is a normal message to display if there is nothing for the changer to read. It also tells me that the navigation is unavailable when I select the button as well. I am not sure if I have to insert the disc for it to work.
Any ideas on what the issue could be? I am leaning towards trying another PCM 2.0 radio. Maybe I can grab one at the Hershey swap meet. In the meantime, does anyone know how the MOST link is daisy chained? Does it go Radio -> Amp -> CD Changer -> Radio? Looking at a picture of an ebay PCM 2.0 navigation module, it does not look like it has a MOST connection based off the plugs on the back of the unit. I do not think my car has a telephone module, as there is nothing under the passenger side seat. Am I missing anything?
