Top front of the motor are two electric vacuum valves. I have seen open circuit in the windings not causing the drop in voltage when the ECM grounds the circuit. Normally applies vacuum to a diaphragm inside Swirl actuator to open up a short intake path when RPM's rise above 3,000. Under rare conditions the ECM ground circuit fails. That is expensive. So what is the code Swirl Control or Curcuit code?