P0451

DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR





Component Description





The EVAP control system pressure sensor (3) detects pressure in the purge line. The sensor output voltage to the ECM increases as pressure increases.
- Illustration shows the view from under the vehicle.
- : Vehicle front
- EVAP canister vent control valve (1)
- EVAP canister (2)




CONSULT-III Reference Value in Data Monitor Mode





Specification data are reference values.









On Board Diagnosis Logic

NOTE:
If DTC P0451 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to P0643.

On Board Diagnosis Logic:

DTC Confirmation Procedure
1. If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Start engine and wait at least 40 seconds.

NOTE:
Do not depress accelerator pedal even slightly.
3. Check 1st trip DTC.
4. If 1st trip DTC is detected, go to P0451.




Diagnosis Procedure
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body. Refer to Power Supply and Ground Circuit.





OK or NG
OK - GO TO 2.
NG - Repair or replace ground connections.
2.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR FOR WATER





1. Disconnect EVAP control system pressure sensor (3) harness connector.
- Illustration shows the view from under the vehicle.
- : Vehicle front
- EVAP canister vent control valve (1)
- EVAP canister (2)
2. Check sensor harness connector for water.

Water should not exist.


OK or NG
OK - GO TO 3.
NG - Repair or replace harness connector.
3.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to P0451.
OK or NG
OK - GO TO 4.
NG - Replace EVAP control system pressure sensor.
4.CHECK INTERMITTENT INCIDENT
Refer to Diagnosis Procedure.
For Wiring Diagram, refer to P0452.
INSPECTION END




Component Inspection

EVAP CONTROL SYSTEM PRESSURE SENSOR
1. Remove EVAP control system pressure sensor with its harness connector.
Always replace O-ring with a new one.
2. Install a vacuum pump to EVAP control system pressure sensor.





3. Turn ignition switch ON and check output voltage between ECM terminal 32 and ground under the following conditions.






CAUTION:
- Always calibrate the vacuum pump gauge when using it.
- Do not apply vacuum below -93.3 kPa (-0.952 kg/cm2, -
13.53 psi) or pressure over 101.3 kPa (1.033 kg/cm2, 14.69 psi).
4. If NG, replace EVAP control system pressure sensor.