P0451

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR

DTC Logic


DTC DETECTION LOGIC







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 CONSULT-GO TO 2.
Without CONSULT-GO TO 5.

2. PERFORM DTC CONFIRMATION PROCEDURE-1

With CONSULT
1.Perform "INSPECTION MODE 5". Description.
2.Start engine and let it idle for least 40 seconds.
NOTE:
Do not depress accelerator pedal even slightly.
3.Check 1st trip DTC.
Is 1st trip DTC detected?
YES- Proceed to .
NO- GO TO 3.

3. PERFORM DTC CONFIRMATION PROCEDURE-2

With CONSULT
1.Select "EVAP DIAG READY" in "DATA MONITOR" mode of "ENGINE".
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 MONITOR" mode of "ENGINE".
6.Check that "EVAP LEAK DIAG" indication.
Which is displayed on CONSULT?
CMPLT- GO TO 4.
YET- 1.Perform DTC CONFIRMATION PROCEDURE again.
2.GO TO 1.

4. PERFORM DTC CONFIRMATION PROCEDURE-3

With CONSULT
Check 1st trip DTC.
Is 1st trip DTC detected?
YES- Proceed to .
NO- INSPECTION END

5. PERFORM DTC CONFIRMATION PROCEDURE-4

With GST
1.Perform "INSPECTION MODE 5". Description.
2.Start engine and let it idle for least 40 seconds.
NOTE:
Do not depress accelerator pedal even slightly.
3.Check 1st trip DTC.
Is 1st trip DTC detected?
YES- Proceed to .
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 .
NO- INSPECTION END


Diagnosis Procedure


1. CHECK GROUND CONNECTION

1.Turn ignition switch OFF.
2.Check ground connection M95. Refer to Ground Inspection in Circuit Inspection.
Is the inspection result normal?
YES- GO TO 2.
NO- Repair or replace ground connection.

2. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR FOR WATER

1.Disconnect EVAP control system pressure sensor harness connector.
2.Check sensor harness connector for water.
Water should not exist.
Is the inspection result normal?
YES- GO TO 3.
NO- Repair or replace harness connector.

3. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY

1.Turn ignition switch ON.
2.Check the voltage between EVAP control system pressure sensor harness connector and ground.





Is the inspection result normal?
YES- GO TO 6.
NO- GO TO 4.

4. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY CIRCUIT

1.Turn ignition switch OFF.
2.Disconnect ECM harness connector.
3.Check the continuity between EVAP control system pressure sensor harness connector and ECM harness connector.





Is the inspection result normal?
YES- GO TO 5.
NO- Repair open circuit.

5. CHECK SENSOR POWER SUPPLY 2 CIRCUIT

Check sensor power supply 2 circuit. Testing and Inspection.
Is the inspection result normal?
YES- GO TO 7.
NO- Repair short to ground or short to power in harness or connectors.

6. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

.
Is the inspection result normal?
YES- GO TO 7.
NO- Replace EVAP control system pressure sensor.

7. CHECK INTERMITTENT INCIDENT

Intermittent Incident.
- INSPECTION END


Component Inspection


1. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

1.Turn ignition switch OFF.
2.Remove EVAP control system pressure sensor with its harness connector.
Always replace O-ring with a new one.
3.Install a vacuum pump to EVAP control system pressure sensor.
4.Turn ignition switch ON and check output voltage between ECM harness connector terminals under the following conditions.






CAUTION:
- Always calibrate the vacuum pump gauge when using it.


22
- Never apply below -93.3 kPa (-0.952 kg/cm, -13.53 psi) or pressure over 101.3 kPa (1.033 kg/cm, 14.69 psi).
Is the inspection result normal?
YES- INSPECTION END
NO- Replace EVAP control system pressure sensor