Radio on no sound

So... I disconnected the battery yesterday to work on the steering wheel/airbag. Waited 30 minutes and everything was fine. Inadvertently left the key on when reconnecting the battery. Went for a short drive... everything seems to be fine ...all systems go, expect no sound from the radio. Radio on, stations intact, buttons function but no sound. Checked the radio and sound fuses both OK. HELP please, prepping for a cross country trip... 2003 cab w/ Boise sound...

Do you have the security code for the radio?

808Bill, I might... I have disconnected in the past with no issues. would the radio screen come on without the code?

Mine (CDR-220) come on, say PORSCHE, and then CODE. You enter the 4 digit code and it unlocks. If you get it wrong too many times it makes you wait, and as I recall says something like WAIT (may not be exactly correct, but something like that).

What CDS said is what I thought should happen. After PORSCHE comes on the screen it goes directly to a station number.

Quotes source post: 15981965

The MOST based radio units don't use the 4 digit security codes like the older analog units. Not needed. The MOST systems are matched to the VIN at the factory/dealership with the PIWIS system. Basically, the CDR-23 (PCM2 or later) has to "handshake" with the ECU at startup. The CDR-23 was the first run of MOST and are known to be problematic. OP, try this... Hold down the TP button AND the 4 preset button for 10 seconds. That should reset the unit. If that doesn't work, you may need to schedule service at your local dealership.

Thanks everyone for your input. After nothing above worked and additional web search,. I decided to treat it like a typical digital based entity... Power down reboot (wait an hour) and everything works *** it should.

You beat me to it. I had the same problem on my 2003 when I was in the process of figuring out the sound system on mine. With the MOST system you definitely want to make sure the head unit and amplifier are all connected up. Unhook the battery, wait a little bit and hook it back up. I even had that not work one time but I repeated and it was fine. I think because the MOST components all talk to each other on power up to make sure they are keyed to the car, I suspect that complicated handshake fails some times. FYI, mine is MOST with amp but with the Becker amp, not the Bose.

my 03 does that sometimes I've found if you push CD, then push FM, it will come back on

Hey mr. i think it could be a problem with the canbus / i2c, I�ve seen that a lot of times with the cayenne models. One thing that might indicate you have such problem is if for example the compressor unit or maybe the easy-entry feature, is living it�s own life, having intermittent problems and the ****ty vehicle keep complaining about remote-key battery low level, no matter how many times you change it. This is likely to be problems with the ignition lock/module and the immobilizing system having trouble communicating. As a result off this, a bunch of electronic crap isn�t working probably, including the radio. If that�s the problem with your 💩 It ain�t gonna be an easy diy �diagnose-repair� thing! This problem ain�t easy to deal with if you doesn�t have a great amount of electronic skills and tools. What you can try doing: This is mostly an short term �fix� but you can give it a try:-) Firstly do a reset on the damm thing by using a good standard aftermarket OBD tool, Autel 500 series or similar device. NB: Always do a failure code reading first and then the erase of codes. (you must send an erase command even if your test shows no errors stored!) when codes are erased, start the engine let it run a minute or so then turn it of and without!! removing the key, lock and unlock the car like this: lock, count to 3, unlock, turn on the ignition(no start). leave ignition on at least one minute but not so long it triggers the battery save mode! start the dumb thing and the head unit is now supposed to turn it self on, then off and stay off. if it doesn�t turn on then off but stay on or not turns on at all, it haven�t been reset by the ecu and I�ll say you are out of luck as a normal diy- guy. If it does the on/off cycle, you should be able to push the button and enjoy it playing your favorite radio station 😎 NB; it will more than likely work for a day or two but might only work for one hour It�s impossible to know. would not surprise me if you end up kicking tires, wondering if you should set it on fire and inherit the insurance money good luck...

^^ That is some "Porsche" magic right there fer sure! Necro thread and some true southern mumble jumble to boot. And, if that doesn't work please consult your crystal ball or magic eight ball for the next steps.

I have found that with the CDR-23 with MOST amp - if there is a problem of no sound, use the key fob to lock and unlock the car. Locking with the fob causes the system to go into power down mode and re-syncs the head unit with the amp. Also - if you have any options programmed in the CDR-23 (think turning on the CDC mode) - they will not function until the head-unit is cycled. Again - easiest way to do that (no pulling fuses..) is to simply use the fob to lock and unlock the car. -Tom

Sorry to raise the dead on this thread but I just had this issue (everything seems fine but no sound) and after reading a LOT of posts I figured out a solution that worked for me (2003 996TT CDR23 Bose system with Bose CD Changer and Amp). First, i don't really use my CD Changer but i checked it and it wasn't working. I checked the fuse under the back cover and it was good. I bought a fiber optic bypass loop on Amazon (less than $10), bypassed the CDC but no luck. It made no difference. I won't bore you with all the things that didn't work and get straight to what did: Bypass the CDC with a fiber optic loop Turn on the ignition key (don't need to start the car), stereo has no sound but otherwise seems fine Power down the stereo by pushing in the left hand radio button Turn off the ignition key Close the door Activate the alarm with the key fob. Wait a couple minutes Deactivate the alarm with the key fob Open the door Turn the ignition key on Power up the stereo with the left hand radio button Sound restored

I've also noticed when my radio does that, if i switch it to CD, than back to radio, it will work, but i loose the tone presets

I just had this same problem; no sound, everything else working as expected. I turned off the car, locked the car with fob, waited a couple of minutes and unlocked with key fob, started the car, and everything I had volume again.

I have seen this a few times over about 10k miles in 2 years. Comes right back after a bit of time.

This is why I prefer the analog cars. Much easier to adapt or upgrade with aftermarket. The first runs of MOST was very buggy. Seems it didn't start smoothing out until the 987/997 cars. On my '03 996, I just decommissioned MOST and rewired it for aftermarket. Worked great for me and much better sound, phone quality and control. However, I wouldn't advise it nor would I do it again. If I was upgrading MOST based system today, I would just bite the bullet and get a PCCM+. That wasn't available 10 years ago.