Heater Control Valve: Testing and Inspection
WATER CONTROL VALVE INSPECTION1. Start the engine and run it at idle speed.
Water Control Valve Inspection:
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 appear in 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.