DTC Advanced Diagnostics: P0450
DTC P0450:Fuel Tank Pressure (FTP) Sensor Out of Range

General Description

The fuel tank pressure (FTP) sensor provides information about the differential pressure of the fuel tank relative to atmospheric pressure. This sensor is required for the powertrain control module (PCM) to diagnose the evaporative emission (EVAP) system. The diagnosis of the FTP sensor consists of functional range check, circuit continuity check, and rationality check of the measured fuel tank pressure. The differential pressure value of the FTP sensor is compared with calibration thresholds to identify open and short circuit failures. If the fuel tank pressure is a specified value, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Multiple
Sequence
None
Duration
10 seconds or more
DTC Type
Two drive cycles, MIL on

Enable Conditions
Condition
Minimum
Maximum
Elapsed time after starting the engine
1 second
–
Outside air temperature
18.5 °F (-7.5 °C)
103.6 °F (39.8 °C)
Barometric pressure [Baro Sensor]
74 kPa (555 mmHg, 21.9 inHg)
–
Vehicle speed [Vehicle Speed]
7 mph (10 km/h)
–
Fuel level
0 L (0 US gal)
41 L (10.8 US gal)
Other
Engine running in idle
Other than during fuel cut-off operation
EVAP canister vent shut valve is commanded open for at least 3 seconds
[ ]: HDS Parameter

Malfunction Threshold
The fuel tank pressure is greater than 6 kPa (45 mmHg, 1.8 inHg) or less than -5 kPa (-38 mmHg, -1.5 inHg) for at least 10 seconds.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
FTP sensor PTANK line short to power
FTP sensor PTANK line short to ground
FTP sensor PTANK line open

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool clear command.