Toyota Tundra Service Manual: Evaporative Emission Control System Pressure Sensor Range / Performance (P0451-P0453)

DTC SUMMARY

HINT:

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

DESCRIPTION

The description can be found in the EVAP (Evaporative Emission) system (See page ).

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 (2 trip detection logic).

   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 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 less than 0.45 V: 42.1 kPa-a (315.8 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 stores the DTC (1 trip detection logic).

3. DTC P0453: Canister pressure sensor voltage high

   If the canister pressure sensor voltage output (pressure) is higher than 4.9 V: 123.8 kPa-a (928.6 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 stores the DTC (1 trip detection logic).

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

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 24 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 higher, 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 menus: 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 menus: Powertrain / Engine and ECT / Utility / Evaporative System Check / Automatic Mode.
8. After the "Evaporative System Check" is completed, check 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.

    Tester Display	Description
    NORMAL	DTC judgment completed System normal
    ABNORMAL	DTC judgment completed System abnormal
    INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
    N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    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 (See page ).

    HINT:

    • If a permanent DTC is output, the system is malfunctioning.
    • If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

Refer to the EVAP system (See page ).

CAUTION / NOTICE / HINT

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.
• The Techstream is required to conduct the following diagnostic troubleshooting procedure.

PROCEDURE

(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.

B

GO TO STEP 4

C

GO TO EVAP SYSTEM

A

(a) Turn the ignition switch off.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

B

GO TO STEP 7

A

(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.

A

GO TO STEP 5

B

GO TO STEP 6

(a) Disconnect the canister pump module connector.

(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:

B

GO TO STEP 6

A

(a) Replace the canister pump module (See page ).

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 the canister and canister pump module together.
• Check for filter blockage in the canister. If the charcoal filter inside the canister is clogged, replace the canister and canister pump module together.
• Check for filter blockage in the canister filter. If the canister filter has blockages, replace the fuel tank inlet pipe sub-assembly.

NEXT

GO TO STEP 8

HINT:

If the exhaust tailpipe has been removed, go to the next step before reinstalling it.

NEXT

GO TO STEP 8

(a) Replace the ECM (See page ).

NEXT

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Clear the DTCs (See page ).

(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) Drive the vehicle in accordance with the 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.

NEXT

END