FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Except For California


DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR





Component Description





The EVAP control system pressure sensor (1) detects pressure in the purge line. The sensor output voltage to the ECM increases as pressure increases.
- This illustration is a view from under vehicle
- EVAP canister (2)
- EVAP canister vent control valve (3)









CONSULT-III Reference Value in Data Monitor Mode
Specification data are reference values.









On Board Diagnosis Logic









DTC Confirmation Procedure

NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.
1. Start engine and wait at least 40 seconds.

NOTE:
Do not depress accelerator pedal even slightly.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to "Diagnosis Procedure".




Diagnosis Procedure
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.





2. Loosen and retighten ground screws on the body. Refer to Except For California.
- Arrow Indicates Vehicle front
- Body ground (1)
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 (1) harness connector.
- This illustration is a view from under vehicle
- EVAP canister (2)
- EVAP canister vent control valve (3)
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 "Component Inspection".
OK or NG
OK >> GO TO 4.
NG >> Replace EVAP control system pressure sensor.
4.CHECK POWER SUPPLY CIRCUITS
Check harness for short to power and short to ground, between the following terminals.





OK or NG
OK >> GO TO 5.
NG >> Repair short to ground or short to power in harness or connectors.
5.CHECK REFRIGERANT PRESSURE SENSOR
Refer to Initial Inspection and Diagnostic Overview Locations.
OK or NG
OK >> GO TO 6.
NG >> Replace refrigerant pressure sensor.
6.CHECK CRANKSHAFT POSITION SENSOR (POS)
Refer to Except For California.
OK or NG
OK >> GO TO 7.
NG >> Replace crankshaft position sensor (POS).
7.CHECK APP SENSOR
Refer to Except For California.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8.REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace accelerator pedal assembly.
2. Perform Except For California.
3. Perform Except For California.
4. Perform Except For California.
>> INSPECTION END
9.CHECK INTERMITTENT INCIDENT
Refer to Except For California Except For California.
For wiring diagram, refer to Except For California.
>> INSPECTION END




Component Inspection

EVAP CONTROL SYSTEM PRESSURE SENSOR
1. Remove EVAP control system pressure sensor with its harness connector connected from EVAP canister.
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 42 and ground under the following conditions.






CAUTION:
- Always calibrate the vacuum pump gauge when using it.
- Do not apply below -93.3 kPa (-700 mmHg, -27.56 inHg) or pressure over 101.3 kPa (760 mmHg, 29.92 inHg).
4. If NG, replace EVAP control system pressure sensor.