Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

CDR-23 Keeps trying to reboot, turning off and on

Recommended Posts

I have a non-Bose CDR-23. that keeps trying to boot-up. It displays Porsche, then repeats the cycle until some time later it finally initializes.

When I pull the fiber optic connector at the CDC-4 unit, the fiber light turns on and off in-synch with the power on/off cycle of the radio.

I am not sure it I have a bad CDR-23 or possibly a fiber issue with the MOST. How do I troubleshoot? I ran a Durametric, and no faults were detected.

Any ideas?

Link to comment
Share on other sites

  • Admin

Have you added or removed anything from the MOST (fiber optic) network recently?

If so, then you may need to re-code the system to identify all of the units on the MOST bus.


Does your car have the Harman amplifier? If so, have you checked it's fuse (D9).


Or your may just have a faulty CDR-23. There are a number of MOST diagnostic test that Porsche diagnostic tools (PST2, PIWIS, PIWIS 2) can run but I doubt Durametric can.

Your best (least expensive) solution may be to find a shop with a Porsche tool and run the full MOST diagnostics to narrow down the problem.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.