DTC P0451: EVAP Pressure Sensor Range/Performance: Description

The control module monitors the fuel tank pressure (FTP) sensor signal in order to detect vacuum decay and excess vacuum during the evaporative emission (EVAP) diagnostic test. The control module supplies a 5-volt reference and a low reference circuit to the FTP sensor. If the FTP sensor signal voltage is not within a calibrated value range during a cold engine start, this DTC sets.

The following table illustrates the relationship between FTP sensor signal voltage and the EVAP system pressure/vacuum. See RELATIONSHIP BETWEEN FTP SENSOR SIGNAL VOLTAGE & EVAP SYSTEM PRESSURE/VACUUM .