FixVault

DTC P0661: Variable Intake-Air Solenoid Valve Circuit Low Input: Notes

WARNING: This page is about a different car, the 2004 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: DTC P0661: Detection Condition & Possible Causes Chart
G00975329Courtesy of MAZDA MOTORS CORP.