Water Valve VSV Circuit

If the target air mix damper position is on the hot side beyond a predetermined level, the A/C control assembly turns ON Tr inside the A/C control assembly.
This turns the water valve VSV ON so that engine coolant flows to the heater core.
If the target air mix damper position is on the cool side beyond a predetermined level, the A/C control assembly OFF Tr inside the A/C control assembly.
This turns OFF the VSV and stops circulation of engine coolant to the heater core, thus increasing the cooling performance.

Diagnostic Chart:

Wiring Diagram:

Inspection Procedure - Step 1:

Step 2:

Step 3: