It is the sensor that has a 2 wire plug going into it on the VTEC solenoid assembly that attaches to the head. To fix it check to make sure you have enough oil in the engine, check the wiring, and then check to make sure the sensor works by either performing tests on it or by switching it with a known good sensor. It seams to go for $64.65 new at the dealership or $45.26+shipping at Majestic Honda.