P0451

DTC P0451 EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR RANGE/PERFORMANCE

CIRCUIT DESCRIPTION

DTC Detection Condition:

The Fuel Tank Pressure (FTP) sensor, the Evaporative Emissions Vacuum Switching Valve (EVAP VSV), Canister Closed Valve (CCV) and by-pass VSV are used to detect abnormalities in the evaporative emission control system.

The ECM decides whether there is an abnormality in the EVAP system, based on the FTP sensor signal.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions Part 1:

Typical Enabling Conditions Part 2:

Typical Malfunction Thresholds:

Component Operating Range:

The ECM monitors the FTP sensor in two ways. One method examines the fluctuation of the electrical signal while the engine is idling.If the pressure signal varies beyond the specified range, the ECM interprets this as a noise in the FTP sensor. The ECM also verifies that the pressure signal changes within the specified range.If the output of the sensor does not vary for 10 minutes while the intake air amount has been changing, the ECM interprets this as a fault in the FTP sensor. Either fault will set DTC P0451 and the ECM will turn on the MIL.

Wiring Diagram:

Step 1 - 3:

Step 4 - 6:

Step 7 - 9:

Step 10:

INSPECTION PROCEDURE

HINT: Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions when a malfunction is detected.When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was LEAN or RICH, etc.at the time of the malfunction.