Try this:
PINPOINT TEST A: VENT DOES NOT OPERATE
² A1: CHECK SYSTEM AIRFLOW
² A2: CHECK VACUUM SUPPLY HOSE CONNECTION
² A3: CHECK VACUUM SUPPLY HOSE FOR LEAKS
² A4: CHECK VACUUM CHECK VALVE FOR CORRECT INSTALLATION
² A5: INSPECT VACUUM CHECK VALVE FOR OBSTRUCTIONS
² A6: LEAK TEST VACUUM CHECK VALVE
² A7: CHECK VACUUM RESERVOIR
² A8: CHECK SUPPLY HOSE
² A9: CHECK CONTROL ASSEMBLY
² A10: LEAK TEST CONTROL ASSEMBLY
² A11: CHECK SUPPLY HOSE FOR BLOCKAGE
² A12: LEAK TEST JUMPER VACUUM HARNESS
² A13: EVALUATE SYSTEM AIR FLOW
² A14: ISOLATE LEAKING VACUUM CIRCUIT
² A15: REVIEW VEHICLE HISTORY
² A16: CHECK VACUUM HOSES FOR OBSTRUCTION
² A17: CHECK VACUUM HARNESS
² A18: CHECK VACUUM CIRCUIT FOR PINCH OR KINK
² A19: CHECK VACUUM CIRCUIT CONNECTIONS
² A20: CHECK VACUUM HOSE FOR LEAKS
² A21: CHECK VACUUM CONTROL MOTOR
² A22: CHECK VACUUM CONTROL MOTOR INSTALLATION
If you need more info, let me know.
