Kia wrote:

I recently purchased a a second hand Pioneer DEH 535R stereo for my
car and initially it was working. Now sometimes when I play a cd it
will stop and say 'ERROR RD', even though the cd is new or scratch
free. However now it refuses to accept the cd into the player,
altogether.

I'd imagine it's trying to flag a Read Error - probably dust and dirt on
the lens. If you can get the top off and get at the laser then a small
paintbrush would clean it up nicely.

--
Scott

Where are we going and why am I in this handbasket?