Heater Control Valve: Testing and Inspection

WATER CONTROL VALVE INSPECTION

1. Start the engine and run it at idle speed.




2. Select mode and check the rod position and vacuum at port A.




3. If rod position and/or vacuum appearance at port A is not as specifications, check the following:
- If vacuum at port A appears in MAX A/C mode but rod position is not correct, replace the water control valve.
- If vacuum at port A appears in A/C, Vent, Panel/Floor, Floor, Floor/Defroster and Defroster modes, check the vacuum control valve.
- If vacuum at port A does not appearing MAX A/C mode, check for leak in a vacuum line and at the vacuum control valve.

NOTE: When replacing the water control valve, connect heater hoses to heater control valve properly.