P0451
P0451 EVAP Control System Pressure Sensor
Component Description
The EVAP control system pressure sensor (2) detects pressure in the purge line. The sensor output voltage to the ECM increases as pressure increases.
- EVAP canister vent control valve (1)
- Drain filter (3)
- EVAP canister (4)
- : Vehicle front
On Board Diagnosis Logic
If DTC P0451 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to [Power Supply and Ground Circuit Check] P0643.
DTC Confirmation Procedure
DTC Confirmation Procedure
NOTE:
Never remove fuel filler cap during DTC confirmation procedure.
1. PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
1 Turn ignition switch OFF and wait at least 10 seconds.
2 Turn ignition switch ON.
3 Turn ignition switch OFF and wait at least 10 seconds.
With SDT
GO TO 2.
Without SDT
GO TO 5.
2. PERFORM DTC CONFIRMATION PROCEDURE-1
With SDT
1 Start engine and let it idle for least 40 seconds.
NOTE:
Do not depress accelerator pedal even slightly.
2 Check 1st trip DTC.
Is 1st trip DTC detected?
YES
Proceed to "Diagnosis Procedure".
NO
GO TO 3.
3. PERFORM DTC CONFIRMATION PROCEDURE-2
With SDT
1 Select "EVAP DIAG READY" in "Data list" mode of "Engine / Powertrain".
2 Let it idle until "OFF" of "EVAP DIAG READY" changes to "ON".
NOTE:
It will take at most 2 hours until "OFF" of "EVAP DIAG READY" changes to "ON".
3 Turn ignition switch OFF and wait at least 90 minutes.
NOTE:
Never turn ignition switch ON during 90 minutes.
4 Turn ignition switch ON.
5 Select "EVAP LEAK DIAG" in "Data list" mode of "Engine / Powertrain".
6 Check that "EVAP LEAK DIAG" indication.
Which is displayed on SDT?
CMPLT
GO TO 4.
YET
1 Perform DTC CONFIRMATION PROCEDURE again.
2 GO TO 1.
4. PERFORM DTC CONFIRMATION PROCEDURE-3
With SDT
Check 1st trip DTC.
Is 1st trip DTC detected?
YES
Proceed to "Diagnosis Procedure".
NO
INSPECTION END
5. PERFORM DTC CONFIRMATION PROCEDURE-4
With GST
1 Start engine and let it idle for least 40 seconds.
NOTE:
Do not depress accelerator pedal even slightly.
2 Check 1st trip DTC.
Is 1st trip DTC detected?
YES
Proceed to "Diagnosis Procedure".
NO
GO TO 6.
6. PERFORM DTC CONFIRMATION PROCEDURE-5
With GST
1 Let it idle for at least 2 hours.
2 Turn ignition switch OFF and wait at least 90 minutes.
NOTE:
Never turn ignition switch ON during 90 minutes.
3 Turn ignition switch ON.
4 Check 1st trip DTC.
Is 1st trip DTC detected?
YES
Proceed to "Diagnosis Procedure".
NO
INSPECTION END
Diagnosis Procedure
1. CHECK GROUND CONNECTIONS
1 Turn ignition switch OFF.
2 Loosen and retighten three ground screws on the body. Refer to Power Supply and Ground Circuit Check.
OK or NG
OK
GO TO 2.
NG
Repair or replace ground connections.
2. CHECK EVPA CONTROL SYSTEM PRESSURE SENSOR CONNECTOR FOR WATER
1 Disconnect EVAP control system pressure sensor (2) harness connector.
- EVAP canister vent control valve (1)
- Drain filter (3)
- EVAP canister (4)
- : Vehicle front
1 Check sensor harness connector for water.
OK or NG
OK
GO TO 3.
NG
Repair or replace harness connector.
3. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to "Component Inspection".
OK or NG
OK
GO TO 4.
NG
Replace EVAP control system pressure sensor. Refer to [EVAP Canister: Removal and Installation] Service and Repair.
4. CHECK INTERMITTENT INCIDENT
Refer to [Service Information for Electrical Incident: Intermittent Incident] Service Information for Electrical Incident: Intermittent Incident.
INSPECTION END
Component Inspection
EVAP Control System Pressure Sensor
1) Remove EVAP control system pressure sensor with its harness connector connected from EVAP canister.
Do not reuse the O-ring, replace it 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.
- Never apply 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.