Radio not holding a few stations
05-01-2012 | 10:22 AM
#1
Thread Starter
Burning Brakes
Joined: Nov 2008
Posts: 1,063
Likes: 214
From: New Hampshire
Radio not holding a few stations
My 2007 911 radio will not hold a few stations. When I tune to 95.7 it will invariably drift to the next station 96.5 then oscillate between the two stations. It does the same thing with 97.7 and 98.7 in a different town.
I went to the stealership and they told me that it is the fault of the radio station and the way they tune their frequency. If I push them they might change out the PCM. I still have 1 year on my CPO warranty. Any suggestions? Is this really a problem with the way the radio station sends out frequency or is this a porsche PCM problem?
Thank you
CB
I went to the stealership and they told me that it is the fault of the radio station and the way they tune their frequency. If I push them they might change out the PCM. I still have 1 year on my CPO warranty. Any suggestions? Is this really a problem with the way the radio station sends out frequency or is this a porsche PCM problem?
Thank you
CB
05-01-2012 | 04:54 PM
#3
Thread Starter
Burning Brakes
Joined: Nov 2008
Posts: 1,063
Likes: 214
From: New Hampshire
I think you are correct. I made an appointment for next Tuesday at another stealership an hour away. They will take a look a the radio and hopefully fix it or get me a new PCM.
05-01-2012 | 08:09 PM
#4
Drifting
Joined: May 2007
Posts: 2,415
Likes: 13
From: Pacific Northwest
Do you have an analog tuned radio (or other radio for that matter) that you can have in the car as well to test with?
When the radio is oscillating, what is oscillating exactly?
Is the tuned in frequency changing on the PCM display or is just the audio content changing that you hear?
If the tuner is set to lock in a specific FM carrier frequency, say 95.7, and when its displaying 95.7 you hear the content of that station and occasionally you hear the 95.5 station content, it may not be the radio's fault. Frequency filters are not perfect, its why we don't have stations at 95.70 and then 95.65 and 95.60 all at the same time; there can be signal bleed over.
Listening on another radio tuner may give you some clue when you hear the PCM content change (assuming the tuner isn't changing the channel its locked in on, just the audio content is changing), to see if it is the radio or the signals the radio is getting.
If one station is broadcasting with a much stronger signal in an adjacent frequency space, it may well bleed onto the adjacent channel enough that you either hear the wrong content, or it may affect the tuning system that locks onto a frequency into locking onto the wrong frequency.
If you had an analog tuned radio where tuning happens by turning a **** that adjusts an inductive coil and/or capacitor directly, then the tuner never changes on its own and you'd likely be able to hear whats really going on. With digital tuners, they tuner senses the main carrier frequency in its window and fine-tunes on its own to lock in on the signal and a badly behaving neighboring frequency or atmospheric effects could cause the signals seen to be such that the autolocking circuit jumps ship to what it thinks is the stronger and correct carrier frequency. That could be a problem in the tuner design (PCM radio) or the stations or assignment of nearby frequencies by the FCC to stations whose transmitters are located near each other..
When the radio is oscillating, what is oscillating exactly?
Is the tuned in frequency changing on the PCM display or is just the audio content changing that you hear?
If the tuner is set to lock in a specific FM carrier frequency, say 95.7, and when its displaying 95.7 you hear the content of that station and occasionally you hear the 95.5 station content, it may not be the radio's fault. Frequency filters are not perfect, its why we don't have stations at 95.70 and then 95.65 and 95.60 all at the same time; there can be signal bleed over.
Listening on another radio tuner may give you some clue when you hear the PCM content change (assuming the tuner isn't changing the channel its locked in on, just the audio content is changing), to see if it is the radio or the signals the radio is getting.
If one station is broadcasting with a much stronger signal in an adjacent frequency space, it may well bleed onto the adjacent channel enough that you either hear the wrong content, or it may affect the tuning system that locks onto a frequency into locking onto the wrong frequency.
If you had an analog tuned radio where tuning happens by turning a **** that adjusts an inductive coil and/or capacitor directly, then the tuner never changes on its own and you'd likely be able to hear whats really going on. With digital tuners, they tuner senses the main carrier frequency in its window and fine-tunes on its own to lock in on the signal and a badly behaving neighboring frequency or atmospheric effects could cause the signals seen to be such that the autolocking circuit jumps ship to what it thinks is the stronger and correct carrier frequency. That could be a problem in the tuner design (PCM radio) or the stations or assignment of nearby frequencies by the FCC to stations whose transmitters are located near each other..
05-01-2012 | 08:43 PM
#5
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Rennlist Member
Joined: Aug 2006
Posts: 4,285
Likes: 118
From: Houston, TX
Try turning off the traffic program option -- it will automatically tune the radio to stations that indicate they are providing traffic updates. If stations abuse the function (it's happened here in Houston a few times) you'll be continuously changed to the offending station. If two stations do this, it will appear like the behavior you describe.
05-01-2012 | 10:45 PM
#6
Rennlist Member
Joined: Nov 2009
Posts: 3,017
Likes: 391
From: PNW
Try turning off the traffic program option -- it will automatically tune the radio to stations that indicate they are providing traffic updates. If stations abuse the function (it's happened here in Houston a few times) you'll be continuously changed to the offending station. If two stations do this, it will appear like the behavior you describe.
05-03-2012 | 05:26 PM
#7
Drifting
Joined: May 2007
Posts: 2,415
Likes: 13
From: Pacific Northwest
Indeed. The traffic program (TP) setting is designed to have your audio system automatically change to a radio station that is using the TP flag on a broadcast, then switch back to the original source when the traffic program is done (TP flag goes away).
The purpose is, in a region a particular station or stations provide meaningful traffic updates and you want to hear them. So it will auto switch whenever those traffic updates are being broadcast.
If your region doesn't provide useful traffic updates or the updates are of no use to you, uncheck the TP option. If its activated there should be a TP indicator in the PCM display for the radio display visible.
The purpose is, in a region a particular station or stations provide meaningful traffic updates and you want to hear them. So it will auto switch whenever those traffic updates are being broadcast.
If your region doesn't provide useful traffic updates or the updates are of no use to you, uncheck the TP option. If its activated there should be a TP indicator in the PCM display for the radio display visible.
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05-03-2012 | 11:02 PM
#8
Rennlist Member
Joined: Jan 2009
Posts: 279
Likes: 86
From: Dallas, TX
Mine does same thing, but only the preset on number 5 which is am FM station. Will randomly tune to some AM talk station and back without warning. All other presets seem fine.
Thoughts? Could it but the traffic thing mentioned earlier?
Thoughts? Could it but the traffic thing mentioned earlier?
05-05-2012 | 11:52 AM
#10
3rd Gear
Joined: Feb 2011
Posts: 3
Likes: 0
Hi, I bought new a 2006 C2S (built in Aug of '05) and the same thing started to happen to my radio within the first 6 months and in the end they had to replace the center console radio/computer. Even back then (with the first set of cars) it was a known issue and they just swapped it out without any questions - that is they did not even really question me about the problem, just did it. Other than that i had whistling in my side mirrors that was fixed with them siliconing where the cover seam met and had a water pump replaced. Since that first 6 months of growing pains i have had a trouble free and fantastic 7 years of ownership over 35k miles and plan to drive her as my DD for as long as she lasts. I would probably even put in a new engine if it came to that vs. the cost of the 991...... but i am a fan of the 6 speed notchiness, the 991 PDK smoothness can pass me on the track but i will be the one screaming with joy double clutching and holding on for dear life on the track or just enjoying having full control over the car in more subdued conditions.
05-08-2012 | 09:55 AM
#11
Thread Starter
Burning Brakes
Joined: Nov 2008
Posts: 1,063
Likes: 214
From: New Hampshire
Indeed. The traffic program (TP) setting is designed to have your audio system automatically change to a radio station that is using the TP flag on a broadcast, then switch back to the original source when the traffic program is done (TP flag goes away).
The purpose is, in a region a particular station or stations provide meaningful traffic updates and you want to hear them. So it will auto switch whenever those traffic updates are being broadcast.
If your region doesn't provide useful traffic updates or the updates are of no use to you, uncheck the TP option. If its activated there should be a TP indicator in the PCM display for the radio display visible.
The purpose is, in a region a particular station or stations provide meaningful traffic updates and you want to hear them. So it will auto switch whenever those traffic updates are being broadcast.
If your region doesn't provide useful traffic updates or the updates are of no use to you, uncheck the TP option. If its activated there should be a TP indicator in the PCM display for the radio display visible.
05-08-2012 | 09:56 AM
#12
Thread Starter
Burning Brakes
Joined: Nov 2008
Posts: 1,063
Likes: 214
From: New Hampshire
Indeed. The traffic program (TP) setting is designed to have your audio system automatically change to a radio station that is using the TP flag on a broadcast, then switch back to the original source when the traffic program is done (TP flag goes away).
The purpose is, in a region a particular station or stations provide meaningful traffic updates and you want to hear them. So it will auto switch whenever those traffic updates are being broadcast.
If your region doesn't provide useful traffic updates or the updates are of no use to you, uncheck the TP option. If its activated there should be a TP indicator in the PCM display for the radio display visible.
The purpose is, in a region a particular station or stations provide meaningful traffic updates and you want to hear them. So it will auto switch whenever those traffic updates are being broadcast.
If your region doesn't provide useful traffic updates or the updates are of no use to you, uncheck the TP option. If its activated there should be a TP indicator in the PCM display for the radio display visible.
05-08-2012 | 10:00 AM
#13
Thread Starter
Burning Brakes
Joined: Nov 2008
Posts: 1,063
Likes: 214
From: New Hampshire
Do you have an analog tuned radio (or other radio for that matter) that you can have in the car as well to test with?
When the radio is oscillating, what is oscillating exactly?
Is the tuned in frequency changing on the PCM display or is just the audio content changing that you hear?
If the tuner is set to lock in a specific FM carrier frequency, say 95.7, and when its displaying 95.7 you hear the content of that station and occasionally you hear the 95.5 station content, it may not be the radio's fault. Frequency filters are not perfect, its why we don't have stations at 95.70 and then 95.65 and 95.60 all at the same time; there can be signal bleed over.
Listening on another radio tuner may give you some clue when you hear the PCM content change (assuming the tuner isn't changing the channel its locked in on, just the audio content is changing), to see if it is the radio or the signals the radio is getting.
If one station is broadcasting with a much stronger signal in an adjacent frequency space, it may well bleed onto the adjacent channel enough that you either hear the wrong content, or it may affect the tuning system that locks onto a frequency into locking onto the wrong frequency.
If you had an analog tuned radio where tuning happens by turning a **** that adjusts an inductive coil and/or capacitor directly, then the tuner never changes on its own and you'd likely be able to hear whats really going on. With digital tuners, they tuner senses the main carrier frequency in its window and fine-tunes on its own to lock in on the signal and a badly behaving neighboring frequency or atmospheric effects could cause the signals seen to be such that the autolocking circuit jumps ship to what it thinks is the stronger and correct carrier frequency. That could be a problem in the tuner design (PCM radio) or the stations or assignment of nearby frequencies by the FCC to stations whose transmitters are located near each other..
When the radio is oscillating, what is oscillating exactly?
Is the tuned in frequency changing on the PCM display or is just the audio content changing that you hear?
If the tuner is set to lock in a specific FM carrier frequency, say 95.7, and when its displaying 95.7 you hear the content of that station and occasionally you hear the 95.5 station content, it may not be the radio's fault. Frequency filters are not perfect, its why we don't have stations at 95.70 and then 95.65 and 95.60 all at the same time; there can be signal bleed over.
Listening on another radio tuner may give you some clue when you hear the PCM content change (assuming the tuner isn't changing the channel its locked in on, just the audio content is changing), to see if it is the radio or the signals the radio is getting.
If one station is broadcasting with a much stronger signal in an adjacent frequency space, it may well bleed onto the adjacent channel enough that you either hear the wrong content, or it may affect the tuning system that locks onto a frequency into locking onto the wrong frequency.
If you had an analog tuned radio where tuning happens by turning a **** that adjusts an inductive coil and/or capacitor directly, then the tuner never changes on its own and you'd likely be able to hear whats really going on. With digital tuners, they tuner senses the main carrier frequency in its window and fine-tunes on its own to lock in on the signal and a badly behaving neighboring frequency or atmospheric effects could cause the signals seen to be such that the autolocking circuit jumps ship to what it thinks is the stronger and correct carrier frequency. That could be a problem in the tuner design (PCM radio) or the stations or assignment of nearby frequencies by the FCC to stations whose transmitters are located near each other..
I will see what the dealership says this morning.
Thanks a lot for the info.
CB
05-08-2012 | 09:35 PM
#14
Thread Starter
Burning Brakes
Joined: Nov 2008
Posts: 1,063
Likes: 214
From: New Hampshire
They checked the firm ware and software in the PCM. I think the firmware has been updated therefore the entire unit must be replaced. I never spoke to the technician after I showed him the videos of the problem so I am not 100% sure this is the case. Hopefully the new PCM will hold the stations better.
I wonder why the other stealership I went to shrugged off the problem, and basically said it was a radio station tuning problem and I had to live with it.
05-11-2012 | 06:03 PM
#15
Drifting
Joined: May 2007
Posts: 2,415
Likes: 13
From: Pacific Northwest
Well, once the new PCM is in place, we will know more. If it persists, then we will have evidence it may be the radio stations.
Did you validate the TP setting was off? If not, that could have been it as well.
Or the PCM radio could have been bad.
Update us once the new radio is in.
Did you validate the TP setting was off? If not, that could have been it as well.
Or the PCM radio could have been bad.
Update us once the new radio is in.