Engine Light code P1009 on 4 cyl 2005 Accord

I have a 2005 Accord 4 cylinder that has the engine light on. I have had it serviced and the code was P1009. First mechanic added oil and reset the light. It came back on, so the problem wasn't low oil. He then replaced the variable timing solenoid and changed the oil and filter. After a week or so, the light came on with same code. I then took it to a foreign car specialist well-skilled in Honda engines. He did a lot of research and confirmed the first mechanic did everything correctly, but he also changed the small screen in the oil passage (related to the VTC solenoid somehow). Light came back on today. The car only has 44,000 miles and was well-maintained, oil checked and replaced regularly, no sludge or buildup. I will return to the mechanic that did the last repair, but they all seem stumped by the return of the P1009 code. Any ideas on how to resolve it?

How about the CAM sensor giving a false signal to the ECM!

I had the same code on my 2005 Accord LX 4cyl. I replaced VALVE ASSY, VTC OIL CONTROL Honda part number 15830-RAA-A01 and this fault has not reappeared again.