P0451

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR





Description





The EVAP control system pressure sensor detects pressure in the purge line. The sensor output voltage to the ECM increases as pressure increases.




DTC Logic

DTC DETECTION LOGIC

DTC DETECTION LOGIC:

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.
GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and wait at least 40 seconds.

NOTE:
Do not depress accelerator pedal even slightly.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES - Go to P0451.
NO - INSPECTION END




Diagnosis Procedure
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connections M16, M70. Refer to Power Supply and Ground Circuit.
Is the inspection result normal?
YES - GO TO 2.
NO - Repair or replace ground connections.
2.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR FOR WATER
1. Disconnect EVAP control system pressure sensor harness connector.
2. Check that water is not inside connectors.
Is the inspection result normal?
YES - GO TO 3.
NO - Repair or replace harness connector.
3.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY CIRCUIT-I
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 10.
NO - GO TO 4.
4.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the harness continuity between EVAP control system pressure sensor harness connector and
ECM harness connector.





Is the inspection result normal?
YES - GO TO 6.
NO - GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
1. Harness connectors B171, B469
2. Harness connectors B418, M66
3. Harness for open between EVAP control system pressure sensor and ECM
Repair open circuit.
6.CHECK SENSOR POWER SUPPLY CIRCUIT
Check harness for short to power and short to ground, between the following terminals.





Is the inspection result normal?
YES - GO TO 7.
NO - Repair short to ground or short to power in harness or connectors.
7.CHECK COMPONENTS
Check the following.
- CKP sensor (Refer to P0335.)
- CMP sensor (bank 2) (Refer to P0340.)
- EVT control position sensor (bank 2) (Refer to P1078.)
- Battery current sensor (Refer to P1550.)
- Refrigerant pressure sensor (Refer to Magnet Clutch.)
Is the inspection result normal?
YES - GO TO 8.
NO - Replace malfunctioning component.
8.CHECK APP SENSOR
Refer to P2122.
Is the inspection result normal?
YES - GO TO 11.
NO - GO TO 9.
9.REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace accelerator pedal assembly
2. Go to P2122.
INSPECTION END
10.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to P0451.
Is the inspection result normal?
YES - GO TO 11.
NO - Replace EVAP control system pressure sensor.
11.CHECK INTERMITTENT INCIDENT
Refer to Description.
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.
- 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).
Is the inspection result normal?
YES - INSPECTION END
NO - Replace EVAP control system pressure sensor