I recently had this problem with the Heidelberg on my 87GL. After a power
interruption resulting from installation of a new radar detector my radio
also went into the SAFe mode.

I found the following website instructive on how to enter the code. I also
learned that many are set at 1111 by default. In my case entering 1111 did
the trick and had me back up quickly.

Hope this helps,
Mark Smith
West Virginia