- Inspect the vacuum supply to the vacuum/electric solenoid (vacuum hose-PPL) while the engine is running. The following conditions need to be met:
- Test each vacuum actuator by disconnecting the vacuum hose and applying vacuum directly to the actuator. Repair or replace a vacuum actuator as needed.
- Reconnect all of the vacuum and electrical connections.
- Run the engine and cycle through the operating modes of the heater-A/C control while observing the valve actuators.
- Inspect for vacuum to the mode valve actuators by noting the mode valve actuator position.
- If a valve actuator retracts incorrectly, replace the vacuum electric solenoid. Refer to Vacuum Electrical Solenoid Replacement .
- If a valve actuator does not retract, inspect for vacuum leaks, restricted hoses, or binding valves and linkages.
| • | The vacuum should be approximately 124 kPa (18 psi) with the engine running. |
| • | The vacuum should remain at approximately 124 kPa (18 psi) when the engine is turned OFF. |
When vacuum is applied, the actuator will retract. Refer to the Air Delivery Vacuum Distribution table below.
Vacuum Actuator Mode | Vacuum Port/Hose Color/Valve | Abnormal Condition Reference | ||||
|---|---|---|---|---|---|---|
Defrost Yellow Defrost Valve | Heater Red Mode Valve | A/C Blue IP Outlet Valve | Bi-Level Brown IP Outlet Valve | Air Recirc Orange Air Inlet Valve | ||
Recirc | Vent | Vacuum | Vacuum | Vent | Vacuum | Air Inlet Actuator Replacement or Air Inlet Valve Replacement in Heating, Ventilation, and Air Conditioning |
Bi-Level | Vent | Vacuum | Vent | Vent | Vent | Mode Actuator Replacement or Mode Valve Replacement in Heating, Ventilation, and Air Conditioning |
Upper | Vent | Vacuum | Vacuum | Vent | Vent | Defroster Valve Actuator Replacement or Defroster Valve Replacement in Heating, Ventilation, and Air Conditioning |
Lower | Vent | Vacuum | Vent | Vacuum | Vacuum | Defroster Valve Actuator Replacement or Defroster Valve Replacement in Heating, Ventilation, and Air Conditioning |
Defog | Vent | Vent | Vent | Vacuum | Vent | Mode Actuator Replacement or Mode Valve Replacement in Heating, Ventilation, and Air Conditioning |
Defrost | Vacuum | Vent | Vent | Vacuum | Vent | Defroster Valve Actuator Replacement or Defroster Valve Replacement in Heating, Ventilation, and Air Conditioning |
Outside Air | Vent | Vacuum | Vent | Vent | Vacuum | Air Inlet Actuator Replacement or Air Inlet Valve Replacement in Heating, Ventilation, and Air Conditioning |
