P0451

Wiring Diagram:

CIRCUIT DESCRIPTION
The sensor is installed on the fuel tank.

It senses the fuel vapor pressure in the fuel tank as compared with barometric pressure and converts it into voltage signal.

ECM (PCM) uses this signal as one of the signals to detect the EVAP system malfunction.

Detecting Condition / Possible Cause:

DTC CONFIRMATION PROCEDURE

WARNING:
- When performing a road test, select a place where there is no traffic or possibility of a traffic accident and be very careful during testing to avoid occurrence of an accident.
- Road test should be carried out with 2 persons, a driver and a tester, on a level road.

1. Turn ignition switch OFF.
2. Clear DTC with ignition switch ON.
3. Check vehicle and environmental condition for:
- Indication of fuel level meter in combination meter: within 1/4 - 3/4
- Altitude (barometric pressure).: 2400 m, 8000 ft or less (560 mm Hg, 75 kPa or more)
- Ambient temp.: -10 °C, 14 °F or higher
- Intake air temp.: 70 °C, 158 °F or lower
- Engine coolant temp.: 70 - 110 °C, 158 - 230 °F
4. Drive vehicle under usual driving condition (described in DTC P0136) for 15 min.
5. Keep vehicle speed at 30 - 40 mph, 50 - 60 kph and hold throttle valve at that opening position for 3 min.
6. Stop vehicle (do not turn ignition switch OFF) and confirm that "EVAP system TEST COMPLETED" is displayed in "READINESS TESTS" mode on scan tool.
If "TEST NOT COMPLETED" is still being displayed, repeat above steps 3.to 5).
7. Run engine at idle for 2 min.
8. Check DTC in "DTC" mode and pending DTC in "ON BOARD TEST" or "PENDING DTC" mode.

Step 1 - 6: