DTC P1450: Unable to Bleed Up Fuel Tank Vacuum

WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2005 Mercury Sable, 2005 Mercury Mountaineer, 2005 Mercury Monterey, 2005 Mercury Montego, and 2005 Mercury Mariner. However, it is still accessible from the selected car via links, so may be relevant.

P1450 - UNABLE TO BLEED UP FUEL TANK VACUUM

Description:	Monitors the fuel vapor vacuum and pressure in the fuel tank. System failure occurs when the EVAP running loss monitor detects excessive fuel tank vacuum with the engine running (but not at idle).
Possible Causes:	Blockages or kinks in the EVAP canister tube or EVAP canister purge outlet tube (between the fuel tank, EVAP the canister purge valve and the EVAP canister) Fuel filler cap stuck closed (no vacuum relief) Contaminated fuel vapor elbow on the EVAP canister Restricted EVAP canister CV solenoid stuck open (partially or fully) Plugged CV solenoid filter EVAP canister purge valve stuck open VREF circuit open (harness near the fuel tank pressure [FTP] sensor, the FTP sensor or the powertrain control module [PCM]) Damaged FTP sensor
Diagnostic Aids:	Visually inspect the EVAP canister inlet port, CV solenoid filter, and canister vent hose assembly for contamination or debris. Check EVAP canister purge valve for vacuum leak.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
All	-	-	GO to HX: Evaporative Emission (EVAP) Monitor and System STEP HX9.