variable valve timing actuator P0012

[niceguyjohn]

I have a question. I have a 2009 CX7 with 95,000 KLMs. It runs great and I am quite happy with it. However, I am getting an intermittent CEL with a code of P0012. I know that is the variable valve timing actuator. The CEL comes on once a week or so for a day and then resets itself. I have checked the coil resistance as per the shop manual and it is perfect I have also removed the valve and gave it a good clean. It seems to be working perfectly. I know intermittent issues are a pain to diagnose. So here is my question. I assume the signal to actuate the valve comes from the PCL. but WHAT condition or sensor tells the PCL to activate it? I am thinking the real problem is a false signal coming upstream of the valve itself. Or it could be coming downstream of it. Any advice would be very much appreciated.
Thanks in advance.

 

[niceguyjohn]

Also, Why does the valve timing need to be retarded by 5 degrees in the first place?