P0451

2TR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0450-P0453: Evaporative Emission Control System Pressure Sensor / Switch


DTC SUMMARY





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

DESCRIPTION

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

MONITOR DESCRIPTION

1. DTC P0450: Canister pressure sensor output abnormal fluctuation

If the canister pressure sensor output rapidly fluctuates between less than 42.1 kPa and more than 123.8 kPa, the ECM interprets this as an open or short circuit malfunction in the canister pressure sensor or its circuit, and stops the EVAP (Evaporative Emission) system monitor. The ECM then illuminates the MIL and sets the DTC (1 trip detection logic).

2. DTC P0451: Canister pressure sensor noise or stuck

If the canister pressure sensor voltage output 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 voltage output 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).

3. DTC P0452: Canister pressure sensor output low

If the canister pressure sensor output is below 42.1 kPa, 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 output high

If the canister pressure sensor output is 123.8 kPa 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





















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 tank 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 to ON (do not start the engine).

(c) Turn the Techstream ON.

(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(e) Read DTCs.

(f) Enter the following menus: Powertrain / Engine and ECT / Data List / Evaporative / Vapor Pressure Pump.

(g) Read the EVAP (Evaporative Emission) pressure displayed on the Techstream.

Result:





C -- GO TO EVAP SYSTEM (EVAP SYSTEM INSPECTION PROCEDURE)

B -- CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)
A -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)





(a) Turn the ignition switch to OFF.

(b) Disconnect the E8 ECM connector.

(c) Measure the resistance between PPMP terminal of the ECM connector and the body ground.

Result:





(d) Reconnect the ECM connector.

B -- REPLACE ECM
A -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)





(a) Disconnect the L1 canister connector.

(b) Disconnect the E8 ECM connector.

(c) Check the resistance between PPMP terminal of the ECM connector and the body ground.

Result:





B -- REPAIR OR REPLACE WIRE HARNESS AND CONNECTOR

A -- REPLACE CHARCOAL CANISTER ASSEMBLY

4. CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)





(a) Disconnect the L1 canister connector.

(b) Turn the ignition switch to ON.

(c) Measure the voltage and resistance of the canister connector.

Standard Voltage and Standard Resistance:





Result:





(d) Reconnect the canister connector.

B -- REPAIR OR REPLACE WIRE HARNESS AND CONNECTOR

A -- REPLACE CHARCOAL CANISTER ASSEMBLY

5. REPLACE CHARCOAL CANISTER ASSEMBLY

(a) Replace the canister assembly Removal.





NOTICE:
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 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)

6. REPAIR OR REPLACE WIRE 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 Removal.

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 to ON and turn the Techstream ON.

(c) Wait for at least 60 seconds.

(d) On the Techstream, 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