Porsche Repair Questions? Ask a Mechanic for Answers ASAP
Hey there, thanks for the question.
Generally the symptom your experiencing is caused by a bad antennae or antennae connection. This was actually fairly common on the 997 because techs would pull the connection when replacing the pollen filter and forget to reconnect it.
lastly, if the antennae connections look good then try rebooting the PCM by holding down 1, 4, and 8 at the same time until it reboots.