P0451
1GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0451-P0453: Evaporative Emission Control System Pressure Sensor Range / Performance
DTC SUMMARY
HINT
The canister pressure sensor is built into the canister pump module.
DESCRIPTION
The circuit description can be found in the EVAP System Component Tests and General Diagnostics.
MONITOR DESCRIPTION
- (a) DTC P0451: Canister pressure sensor noise or fixed/flat
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).
- (b) DTC P0452: Canister pressure sensor voltage low
If the canister pressure sensor voltage output [pressure] is below 0.45 V [42.1 kPa-a (315.7 mmHg-a)], 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).
- (c) DTC P0453: Canister pressure sensor voltage high
If the canister pressure sensor voltage output [pressure] is 4.9 V [123.8 kPa-a (928.5 mmHg-a)] 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 (Fixed/Flat Monitor)
P0452 and P0453
TYPICAL MALFUNCTION THRESHOLDS
P0451: Canister Pressure Sensor Noise
P0451: Canister Pressure Sensor Voltage Fixed
P0452: Canister Pressure Sensor Low Voltage
P0453: Canister Pressure Sensor High Voltage
CONFIRMATION DRIVING PATTERN
NOTICE:
* The Evaporative System Check (Automatic Mode) consists of 5 steps performed automatically by the Techstream. It takes a maximum of approximately 19 minutes.
* Do not perform the Evaporative System Check when the fuel tank is more than 90% full because the cut-off valve may be closed, making the fuel tank leak check unavailable.
* Do not run the engine during this operation.
* When the temperature of the fuel is 35°C (95°F) or more, a large amount of vapor forms and any check results become inaccurate. When performing the Evaporative System Check, keep the fuel temperature below 35°C (95°F).
1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON and turn the Techstream on.
3. Enter the following menu items: Powertrain / Engine and ECT / Data List / Intake Air.
4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).
5. Turn the ignition switch off and wait for at least 30 seconds.
6. Turn the ignition switch to ON and turn the Techstream on.
7. Enter the following menu items: Powertrain / Engine and ECT / Utility / Evaporative System Check / Automatic Mode.
8. After the EVAP SYSTEM CHECK is completed, check for All Readiness by entering the following menus: Powertrain / Engine and ECT / Utility / All readiness.
9. Input the DTC: P0451, P0452 or P0453.
10. Check the DTC judgment result.
HINT
If the judgment result shows ABNORMAL, the system has a malfunction.
11. If the test result is INCOMPLETE or UNKNOWN and no pending DTC is output, perform a universal trip and check for permanent DTCs DTC Check / Clear.
HINT
* If a permanent DTC is output, the system is malfunctioning.
* If no permanent DTC is output, the system is normal.
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.
* Inspect the fuses for circuits related to this system before performing the following inspection 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 / All Data / Vapor Pressure Pump.
(g) Read the EVAP (Evaporative Emission) pressure displayed on the Techstream.
Result
C -- GO TO EVAP INSPECTION PROCEDURE Component Tests and General Diagnostics
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 off.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
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 canister connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Result
(d) Reconnect the canister connector.
(e) Reconnect the ECM connector.
B -- REPAIR OR REPLACE HARNESS AND CONNECTOR
A -- REPLACE CANISTER ASSEMBLY
4. CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)
(a) Disconnect the canister connector.
(b) Turn the ignition switch to ON.
(c) Measure the voltage and resistance according to the value(s) in the table below.
Standard Voltage:
Standard Resistance:
Result
(d) Reconnect the canister connector.
B -- REPAIR OR REPLACE HARNESS AND CONNECTOR
A -- REPLACE CANISTER ASSEMBLY
5. REPLACE 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 HARNESS AND CONNECTOR
HINT
If the exhaust tail pipe 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.
(c) Turn the Techstream on.
(d) Clear the DTCs DTC Check / Clear.
(e) Turn the ignition switch off and wait for at least 30 seconds.
(f) Turn the ignition switch to ON and turn the Techstream on.
(g) Start the engine and warm it up.
(h) Refer to the confirmation driving pattern.
(i) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(j) Input the DTC: P0451, P0452 or P0453.
(k) Check the DTC judgment result.
NEXT -- END