DTC P0451: Evaporative Emission System Pressure Sensor/Switch Range/Performance

P0451 - EVAPORATIVE EMISSION SYSTEM PRESSURE SENSOR/SWITCH RANGE/PERFORMANCE

Description:	Note: For some vehicle applications, DTC P0451 is set for a fuel tank pressure (FTP) sensor range (offset) concern. The DTC P0454 replaces the original P0451 for intermittent (noisy) sensor concerns. Until the phase in process is complete, noisy or offset FTP sensor concerns may set a P0451. The fuel tank pressure changes greater than 14 inches of water in 0.10 seconds. FTP sensor output is offset by + /- 1.7 inches H2O.
Possible Causes:	Intermittent open or short in the FTP sensor or the FTP sensor signal Contaminated or damaged sensor Damaged powertrain control module (PCM)
Diagnostic Aids:	Monitor the FTP PID and note if it changes from above 15 inches of water to below minus (-) 15 inches of water often in 1 minute. With the FTP sensor at atmospheric pressure, the FTP PID normally indicates 0 inches of H2O. Look for a minimum reading of +/- 1.7 inches of water as an indication of an offset condition.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
All	GO to Pinpoint Test HX .