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DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-351
< SERVICE INFORMATION >
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DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
Component DescriptionINFOID:0000000001702858
The EVAP control system pressure sensor (1) detects pressure in
the purge line. The sensor output voltage to the ECM increases as
pressure increases.
• EVAP canister (2)
• EVAP canister vent control valve (3)
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000001702859
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001702860
DTC Confirmation ProcedureINFOID:0000000001702861
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.
WITH CONSULT-II
1. Turn ignition switch OFF and wait at least 10 seconds.
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PBIB1207E
MONITOR ITEM CONDITION SPECIFICATION
EVAP SYS PRES • Ignition switch: ON Approx. 1.8 - 4.8V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0451
0451EVAP control system
pressure sensor perfor-
manceECM detects a sloshing signal from the EVAP
control system pressure sensor• Harness or connectors
[Crankshaft position sensor (POS) circuit
is shorted.]
(Accelerator pedal position sensor circuit
is shorted.)
(Refrigerant pressure sensor circuit is
shorted.)
• EVAP control system pressure sensor
• Crankshaft position sensor (POS)
• Accelerator pedal position sensor
• Refrigerant pressure sensor
Page 1426 of 2771

EC-352
< SERVICE INFORMATION >
DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
2. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
3. Start engine and wait at least 40 seconds.
NOTE:
Do not depress accelerator pedal even slightly.
If 1st trip DTC is detected, go to EC-352, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnosis ProcedureINFOID:0000000001702862
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
Refer to EC-142, "
Ground Inspection".
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 (1) harness
connector.
- EVAP canister (2)
- EVAP canister vent control valve (3)
2. Check sensor harness connector for water.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace harness connector.
3.CHECK COMPONENTS POWER SUPPLY
Check harness for short to power and short to ground, between the following terminals.
SEF194Y
:Vehicle front
1. Body ground E24 2. Engine ground F9 3. engine ground F16
4. Body ground E15
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Water should not exist.
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Page 1427 of 2771

DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-353
< SERVICE INFORMATION >
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OK or NG
OK >> GO TO 4.
NG >> Repair short to ground or short to power in harness or connectors.
4.CHECK COMPONENTS
Check the following.
• Refrigerant pressure sensor (Refer to MTC-22
.)
• Crankshaft position sensor (POS) (Refer to EC-301, "
Component Inspection".)
OK or NG
OK >> GO TO 5.
NG >> Replace malfunctioning components.
5.CHECK APP SENSOR
Refer to EC-485, "
Component Inspection".
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace accelerator pedal assembly.
2. Perform EC-76, "
Accelerator Pedal Released Position Learning".
3. Perform EC-76, "
Throttle Valve Closed Position Learning".
4. Perform EC-76, "
Idle Air Volume Learning".
>>INSPECTION END
7.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-353, "
Component Inspection".
OK or NG
OK >> GO TO 8.
NG >> Replace EVAP control system pressure sensor.
8.CHECK INTERMITTENT INCIDENT
Refer to EC-136
.
For wiring diagram, refer to EC-357, "
Wiring Diagram".
>>INSPECTION END
Component InspectionINFOID:0000000001702863
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.
ECM terminal Sensor terminal Reference Wiring Diagram
74 Refrigerant pressure sensor terminal 3EC-542, "
Wiring Diagram"
75 Crankshaft position sensor (POS) terminal 1EC-297, "Wiring Diagram"
76 EVAP control system pressure sensor terminal 3EC-357, "Wiring Diagram"
102 APP sensor terminal 5EC-482, "Wiring Diagram"
Page 1428 of 2771
EC-354
< SERVICE INFORMATION >
DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
3. Turn ignition switch ON and check output voltage between ECM
terminal 42 (EVAP control system pressure sensor signal) 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.
Applied vacuum kPa
(mmHg, inHg)Voltage V
Not applied 1.8 - 4.8
-26.7 (-200, -7.87) 2.1 to 2.5V lower than above value
PBIB3314E
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DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-355
< SERVICE INFORMATION >
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DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
Component DescriptionINFOID:0000000001702864
The EVAP control system pressure sensor (1) detects pressure in
the purge line. The sensor output voltage to the ECM increases as
pressure increases.
• EVAP canister (2)
• EVAP canister vent control valve (3)
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000001702865
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001702866
DTC Confirmation ProcedureINFOID:0000000001702867
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.
TESTING CONDITION:
Always perform test at a temperature of 5°C (41°F) or more.
BBIA0693E
PBIB1207E
MONITOR ITEM CONDITION SPECIFICATION
EVAP SYS PRES • Ignition switch: ON Approx. 1.8 - 4.8V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0452
0452EVAP control system
pressure sensor low in-
putAn excessively low voltage from the sensor is
sent to ECM.• Harness or connectors
(EVAP control system pressure sensor
circuit is open or shorted.)
[Crankshaft position sensor (POS) circuit
is shorted.)
(Accelerator pedal position sensor circuit
is shorted.)
(Refrigerant pressure sensor circuit is
shorted.)
• EVAP control system pressure sensor
• Crankshaft position sensor (POS)
• Accelerator pedal position sensor
• Refrigerant pressure sensor
Page 1430 of 2771
EC-356
< SERVICE INFORMATION >
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Select “DATA MONITOR” mode with CONSULT-II.
5. Make sure that “FUEL T/TMP SE” is more than 0°C (32°F).
6. Start engine and wait at least 20 seconds.
If 1st trip DTC is detected, go to EC-358, "
Diagnosis Procedure".
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Check that voltage between ECM terminal 43 (Fuel tank temper-
ature sensor signal) and ground is less than 4.2V.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and wait at least 20 seconds.
5. Select Service $07 with GST.
If 1st trip DTC is detected, go to EC-358, "
Diagnosis Procedure".
SEF194Y
SEF113U
Page 1431 of 2771
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-357
< SERVICE INFORMATION >
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Wiring DiagramINFOID:0000000001702868
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
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Page 1432 of 2771

EC-358
< SERVICE INFORMATION >
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
Diagnosis Procedure
INFOID:0000000001702869
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
Refer to EC-142, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK CONNECTOR
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
42 VEVAP control system pres-
sure sensor[Ignition switch: ON]Approximately 1.8 - 4.8V
51 OSensor ground
(EVAP control system pres-
sure sensor)[Engine is running]
•Warm-up condition
• Idle speedApproximately 0V
74 WSensor power supply
(Refrigerant pressure
sensor)[Ignition switch: ON]Approximately 5V
75 BRSensor power supply
[Crankshaft position sensor
(POS)][Ignition switch: ON]Approximately 5V
76 WEVAP control system pres-
sure sensor power supply[Ignition switch: ON]Approximately 5V
102 SBSensor power supply
(Accelerator pedal position
sensor 2)[Ignition switch: ON]Approximately 5V
:Vehicle front
1. Body ground E24 2. Engine ground F9 3. Engine ground F16
4. Body ground E15
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