Possible Causes
WARNING: This page is about a different car, the 2003 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.
DTC is set if abnormality exists in the engine vacuum for HCAC system. Possible causes are:
- Defective vacuum hose or line.
- Defective HCAC VSV.
- Defective vacuum sensor.
- Defective check valve.