P0451: EVAP System Ftp Sensor Range/Performance/Intermittent

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P0451 - EVAP SYSTEM FTP SENSOR RANGE/PERFORMANCE/INTERMITTENT

Description:	NOTE: Starting on some 2004 applications, DTC P0451 will be set for a Fuel Tank Pressure FTP sensor range (offset) fault. DTC P0454 will replace the original P0451 for intermittent (noisy) sensor faults. Until the phase in process is complete, noisy or offset FTP sensor faults 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. PCM damaged.
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: EVAPORATIVE EMISSION (EVAP) MONITOR AND SYSTEM Step 49.