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Home >> Lexus >> 2009 >> SC 430 V8-4.3L (3UZ-FE) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P0451

P0451








3UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0450: Evaporative Emission Control System Pressure Sensor Malfunction

DTC P0450 - Evaporative Emission Control System Pressure Sensor Malfunction

DTC P0451 - Evaporative Emission Control System Pressure Sensor Range / Performance

DTC P0452 - Evaporative Emission Control System Pressure Sensor / Switch Low Input

DTC P0453 - Evaporative Emission Control System Pressure Sensor / Switch High Input

DTC SUMMARY





HINT: The canister pressure sensor is built into the canister pump module.

DESCRIPTION

The circuit description can be found in the Evaporative Emission (EVAP) system EVAP System.

MONITOR DESCRIPTION





1 DTC P0450: Canister pressure sensor voltage abnormal fluctuation
If the canister pressure sensor output voltage rapidly fluctuates between less than 0.45 V and more than 4.9 V, the ECM interprets this as an open or short circuit malfunction in the canister pressure sensor or its circuit, and stops the EVAP system monitor. The ECM then illuminates the MIL and sets the DTC (1 trip detection logic).
2 DTC P0451: Canister pressure sensor noisy or stuck
If the canister pressure sensor output voltage fluctuates rapidly for 10 seconds, the ECM stops the EVAP system monitor. The ECM interprets this as noise from the canister pressure sensor, and stops the EVAP system monitor. The ECM then illuminates the MIL and sets the DTC.
Alternatively, if the sensor output voltage does not change for 10 seconds, the ECM interprets this as the sensor being stuck, and stops the monitor. The ECM then illuminates the MIL and sets the DTC.
(Both of the malfunctions are detected by 2 trip detection logic.)
3 DTC P0452: Canister pressure sensor voltage low
If the canister pressure sensor output voltage is below 0.45 V, the ECM interprets this as an open or short circuit malfunction in the canister pressure sensor or its circuit, and stops the EVAP system monitor. The ECM then illuminates the MIL and sets the DTC (1 trip detection logic).
4 DTC P0453: Canister pressure sensor voltage high
If the canister pressure sensor output voltage is 4.9 V or more, the ECM interprets this as an open or short circuit malfunction in the canister pressure sensor or its circuit, and stops the EVAP system monitor. The ECM then illuminates the MIL and sets the DTC (1 trip detection logic).

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

P0451 (Noise Monitor):





P0451 (Stuck Monitor):





P0450, P0452 and P0453:





TYPICAL MALFUNCTION THRESHOLDS

P0450: Canister pressure sensor chattering





P0451: Canister pressure sensor noise





P0451: Canister pressure sensor stuck





P0452: Canister pressure sensor low voltage





P0453: Canister pressure sensor high voltage





COMPONENT OPERATING RANGE





WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE:
- When a vehicle is brought into the workshop, leave it as it is. Do not change the vehicle condition. For example, do not tighten the fuel cap.
- Do not disassemble the canister pump module.
- The Techstream is required to conduct the following diagnostic troubleshooting procedure.

PROCEDURE

1. CONFIRM DTC AND EVAP PRESSURE
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch ON and turn the Techstream ON.
(c) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(d) Read the values.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List / Vapor Pressure Pump.
(f) Read the EVAP pressure displayed on the Techstream.
Result:






C -- CHECK WIRE HARNESS (CANISTER PUMP MODULE - ECM)
A -- GO TO EVAP SYSTEM
B -- Continue to next step.
2. CHECK WIRE HARNESS (CANISTER PUMP MODULE - ECM)




(a) Disconnect the E5 ECM connector.
(b) Turn the ignition switch OFF.
(c) Measure the resistance of the wire harness side connector.
Result:






B -- REPLACE ECM
A -- Continue to next step.
3. CHECK WIRE HARNESS (CANISTER PUMP MODULE - ECM)




(a) Disconnect the C12 canister connector.
(b) Disconnect the E5 ECM connector.
(c) Measure the resistance of the wire harness side connector.
Result:






B -- REPAIR OR REPLACE HARNESS AND CONNECTOR
A -- Continue to next step.
4. CHECK WIRE HARNESS (CANISTER PUMP MODULE - ECM)




(a) Disconnect the C12 canister connector.
(b) Turn the ignition switch ON.
(c) Measure the voltage and resistance of the canister pump module connector.
Standard voltage:






Standard resistance:






Result:






B -- REPAIR OR REPLACE HARNESS AND CONNECTOR
A -- Continue to next step.
5. REPLACE CANISTER ASSEMBLY
(a) Replace the canister assembly Removal.
NOTE:
When replacing the canister, check the canister pump module interior and related pipes for water, fuel or other liquids. If liquids are present, check for disconnections and/or cranks in the following: 1) the pipe from the air inlet port to the canister pump module; 2) the canister filter; and 3) the fuel tank vent hose.

NEXT -- CHECK WHETHER DTC OUTPUT RECURS (AFTER REPAIR)
6. REPAIR OR REPLACE HARNESS AND CONNECTOR
HINT: If the exhaust tailpipe has been removed, go to the next step before reinstalling it.

NEXT -- CHECK WHETHER DTC OUTPUT RECURS (AFTER REPAIR)
7. REPLACE ECM
(a) Replace the ECM.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (AFTER REPAIR)
8. CHECK WHETHER DTC OUTPUT RECURS (AFTER REPAIR)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Wait for at least 60 seconds.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
HINT: If no pending DTC is displayed on the Techstream, the repair has been successfully completed.

NEXT -- COMPLETED
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