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 (Evaporative Emission) System EVAP System.
MONITOR DESCRIPTION
1. 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 stores 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 stores the DTC (Both the malfunctions are detected by 2 trip detection logic).
2. DTC P0452: Canister pressure sensor voltage low
If the canister pressure sensor voltage output (pressure) is below 0.45 V: 42.11 kPa(abs) [315.85 mmHg(abs)], 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 stores the DTC (1 trip detection logic).
3. DTC P0453: Canister pressure sensor voltage high
If the canister pressure sensor voltage output (pressure) is 4.9 V: 123.761 kPa(abs) [928.28 mmHg(abs)] 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 stores the DTC (1 trip detection logic).
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All
P0451: Noise Monitor
P0451: Stuck Monitoring
P0452 and P0453
TYPICAL MALFUNCTION THRESHOLDS
P0451: Canister Pressure Sensor Noise
P0451: Canister Pressure Sensor Stuck Monitoring
P0452: Canister Pressure Sensor Low Voltage
P0453: Canister Pressure Sensor High Voltage
CONFIRMATION DRIVING PATTERN
NOTICE:
* The Evaporative System Check (Automatic Mode) consists of 6 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 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 Evaporative 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 N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.
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.
HINT
Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
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 / Vapor Pressure Pump.
(g) Read the EVAP (Evaporative Emission) pressure displayed on the Techstream.
Result
B -- CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)
C -- GO TO EVAP SYSTEM EVAP System
A -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)
(a) Disconnect the ECM connector.
(b) Measure the resistance according to the value(s) in the table below.
Result
B -- REPLACE ECM
A -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)
(a) Disconnect the canister pump module connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Result
A -- REPLACE CANISTER PUMP MODULE
B -- REPAIR OR REPLACE HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)
4. CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)
(a) Disconnect the canister connector.
Text in Illustration
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
(c) Turn the ignition switch to ON.
(d) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Result
B -- REPAIR OR REPLACE HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)
A -- Continue to next step.
5. REPLACE CANISTER PUMP MODULE
(a) Replace the canister pump module Removal.
Text in Illustration
NOTICE:
* When replacing the canister pump module, check the canister pump module interior, canister 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. If liquids are present in the canister interior, replace canister and canister pump module together (replace canister assembly).
* Check for filter blockage in the canister. If the charcoal filter inside the canister is clogged, replace canister and the canister pump module together (replace canister assembly).
* Check for filter blockage in the canister filter. If the canister filter has blockages, replace the canister filter.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P0451, P0452 OR P0453)
6. REPAIR OR REPLACE HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)
HINT
If the exhaust tail pipe has been removed, go to the next step before reinstalling it.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P0451, P0452 OR P0453)
7. REPLACE ECM
(a) Replace the ECM Removal.
NEXT -- Continue to next step.
8. CHECK WHETHER DTC OUTPUT RECURS (DTC P0451, P0452 OR P0453)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Clear DTCs Reading and Clearing Diagnostic Trouble Codes.
(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) Driving the vehicle in accordance with the driving confirmation driving pattern described in 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.
Result
NEXT -- END