P0451

2GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0451: Evaporative Emission Control System Pressure Sensor Range / Performance

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 pressure sensor is built into the pump module.

DESCRIPTION

The circuit description can be found in the EVAP (Evaporative Emission) System (Component Tests and General Diagnostics).

MONITOR DESCRIPTION





1 DTC P0451: Pressure sensor noising or stuck
If the pressure sensor output voltage fluctuates rapidly for 10 seconds, the ECM stops the EVAP system monitor. The ECM interprets this as noise from the 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 the malfunctions are detected by 2 trip detection logic).
2 DTC P0452: Pressure sensor voltage low
If the pressure sensor output voltage is below 0.45 V, the ECM interprets this as an open or short circuit malfunction in the 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).
3 DTC P0453: Pressure sensor voltage high
If the pressure sensor voltage output is 4.9 V or more, the ECM interprets this as an open or short circuit malfunction in the 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

P0452 and P0453 (Pressure sensor chattering, low voltage, high voltage):





P0451 (Pressure sensor noise):





P0451 (Pressure sensor stuck):





TYPICAL MALFUNCTION THRESHOLDS

P0451: Pressure sensor noise





P0451: Pressure sensor stuck





P0452: Pressure sensor low voltage





P0453: Pressure sensor high voltage





WIRING DIAGRAM





INSPECTION PROCEDURE

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

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (PUMP MODULE - ECM)





(a) Disconnect the N17 canister connector.
(b) Turn the ignition switch on (IG).
(c) Measure the voltage and resistance according to the value(s) in the table below.
Standard voltage:





Result:





(d) Reconnect the canister connector.
B -- CHECK HARNESS AND CONNECTOR
A -- Continue to next step.
2. REPLACE CHARCOAL 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 and other liquids. If liquids are present, check for disconnections and/or cracks 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)
3. CHECK HARNESS AND CONNECTOR





(a) Disconnect the N17 canister pump module connector.
(b) Disconnect the C55 ECM connector.
(c) Measure the resistance between the terminals of the wire harness side connectors.
Standard resistance (Check for open):





Standard resistance (Check for short):





(d) Reconnect the canister pump module connector.
(e) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. REPLACE ECM
(a) Replace the ECM (Removal).
NEXT -- Continue to next step.
5. CHECK WHETHER DTC OUTPUT RECURS (AFTER REPAIR)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch on (IG) (do not start the engine).
(c) Turn the tester on.
(d) Wait for at least 60 seconds.
(e) Enter the following menus: Powertrain / Engine / Trouble Code / Pending.

HINT: If no pending DTCs are displayed on the tester, the repair has been successfully completed.

NEXT -- COMPLETED