Health check
1. Start the engine and let it warm up to operating temperature. Disconnect hose No. 14 from the vacuum manifold and connect a vacuum gauge. There should be a vacuum indicating the on state of the two-way valve, in which the vacuum path to the economizer valve is blocked.
2. If there is no vacuum, then check the assembly for leaks (presence of leaks). You also need to make sure there is 12 volts between the green/yellow and black wires of the solenoid valve when the engine is idling.
3. If there is no voltage at the solenoid valve, then check the green/yellow wiring connecting the valve to the ECU. If there are no open or short circuits in the wiring, then the ECU is either defective or not receiving correct data from the measuring sensors.