Toyota Tundra Service Manual: Evaporative Emission Control System Leak Detected (Gross Leak) (P0455,P0456)

Toyota Tundra Service Manual / Engine, Hybrid System / 1ur-fe Engine Control / Sfi System / Evaporative Emission Control System Leak Detected (Gross Leak) (P0455,P0456)

DTC SUMMARY

DTC No.

Monitoring Item

Malfunction Detection Condition

Trouble Area

Detection Timing

Detection Logic

P0455

EVAP gross leak

Leak detection pump creates negative pressure (vacuum) in EVAP system and EVAP system pressure measured. Reference pressure measured at start and at end of leak check.

If stabilized pressure higher than [second reference pressure x 0.2], ECM determines that EVAP system has large leak.

  • Fuel tank cap (loose)
  • Leak from EVAP line

    (Canister - Fuel tank)

  • Leak from EVAP line

    (Purge VSV - Canister)

  • Canister pump module
  • Leak from fuel tank
  • Leak from canister

While ignition switch off

2 trip

P0456

EVAP small leak

Leak detection pump creates negative pressure (vacuum) in EVAP system and EVAP system pressure measured. Reference pressure measured at start and at end of leak check.

If stabilized pressure higher than second reference pressure, ECM determines that EVAP system has small leak.

  • Fuel tank cap (loose)
  • Leak from EVAP line

    (Canister - Fuel tank)

  • Leak from EVAP line

    (Purge VSV - Canister)

  • Canister pump module
  • Leak from fuel tank
  • Leak from canister

While ignition switch off

2 trip

DESCRIPTION

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

CAUTION / NOTICE / HINT

Refer to the EVAP system (See page ).

MONITOR DESCRIPTION

5 hours* after the ignition switch is turned off, the leak detection pump creates negative pressure (vacuum) in the EVAP system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.

HINT:

*: If the engine coolant temperature is not below 35°C (95°F) 5 hours after the ignition switch is turned off, the monitor check starts 2 hours later. If it is still not below 35°C (95°F) 7 hours after the ignition switch is turned off, the monitor check starts 2.5 hours later.

Sequence

Operation

Description

Duration

-

ECM activation

Activated by soak timer 5, 7 or 9.5 hours after ignition switch turned off.

-

A

Atmospheric pressure measurement

Vent valve turned OFF (vent) and EVAP system pressure measured by ECM in order to register atmospheric pressure.

If pressure in EVAP system not between 70 kPa-a and 110 kPa-a (525 mmHg-a and 825 mmHg-a), ECM cancels EVAP system monitor.

60 seconds

B

First reference pressure measurement

In order to determine reference pressure, leak detection pump creates negative pressure (vacuum) through reference orifice and then ECM checks if leak detection pump and vent valve operate normally.

360 seconds

C

EVAP system pressure measurement

Vent valve turned ON (closed) to shut EVAP system.

Negative pressure (vacuum) created in EVAP system, and EVAP system pressure then measured.

Write down measured value as it will be used in leak check.

If EVAP pressure does not stabilize within 15 minutes, ECM cancels EVAP system monitor.

15 minutes*

D

Purge VSV monitor

Purge VSV opened and then EVAP system pressure measured by ECM.

Large increase indicates normality.

10 seconds

E

Second reference pressure measurement

After second reference pressure measurement, leak check performed by comparing first and second reference pressure.

If stabilized system pressure higher than second reference pressure, ECM determines that EVAP system leaking.

60 seconds

-

Final check

Atmospheric pressure measured and then monitoring result recorded by ECM.

-

*: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.

  • (a) P0455: EVAP gross leak

    In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP system and the EVAP system pressure is measured. If the stabilized system pressure is higher than [second reference pressure x 0.2] (near atmospheric pressure), the ECM determines that the EVAP system has a large leak, illuminates the MIL and stores the DTC (2 trip detection logic).

  • (b) P0456: EVAP very small leak

    In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP system and the EVAP system pressure is measured. If the stabilized system pressure is higher than the second reference pressure, the ECM determines that the EVAP system has a small leak, illuminates the MIL and stores the DTC (2 trip detection logic).

MONITOR STRATEGY

Required Sensors/Components

Purge VSV and canister pump module

Frequency of Operation

Once per driving cycle

Duration

Within 20 minutes (varies with amount of fuel in tank): P0455 (Pattern 1) and P0456

Within 15 minutes (varies with amount of fuel in tank): P0455 (Pattern 2)

MIL Operation

2 driving cycles

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever following DTCs not present

P0452, P0453 (EVAP system)

P0455 (Pattern 1), P0456

Atmospheric pressure

70 to 110 kPa-a (525 to 825 mmHg-a)

Battery voltage

10.5 V or more

Vehicle speed

Below 4 km/h (2.5 mph)

Ignition switch

Off

Time after key off

5, 7 or 9.5 hours

Purge VSV

Not operated by scan tool

Vent valve

Not operated by scan tool

Leak detection pump

Not operated by scan tool

Both of following conditions met before key off

Conditions 1 and 2

1. Duration that vehicle driven

5 minutes or more

2. EVAP purge operation

Performed

ECT

4.4 to 35°C (40 to 95°F)

IAT

4.4 to 35°C (40 to 95°F)

P0455 (Pattern 2)

Atmospheric pressure

70 to 110 kPa-a (525 to 825 mmHg-a)

Battery voltage

10.5 V or more

Vehicle speed

Below 4 km/h (2.5 mph)

Ignition switch

Off

Purge VSV

Not operated by scan tool

Vent valve

Not operated by scan tool

Leak detection pump

Not operated by scan tool

Both of the following conditions 1 and 2 met before key off

-

1. Duration that vehicle has been driven

5 minutes or more

2. EVAP purge operation

Performed

ECT

4.4 to 40°C (40 to 104°F)

IAT

4.4 to 40°C (40 to 104°F)

TYPICAL MALFUNCTION THRESHOLDS

P0455 (Gross leak)

EVAP pressure when vacuum introduction complete

Higher than reference pressure x 0.2

P0456 (Small leak)

EVAP pressure when vacuum introduction complete

Between reference pressure and reference pressure x 0.2

MONITOR RESULT

Refer to Checking Monitor Status (See page ).

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. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
  4. Turn the ignition switch off and wait for at least 30 seconds.
  5. Turn the ignition switch to ON and turn the Techstream on.
  6. Enter the following menus: Powertrain / Engine and ECT / Utility / Evaporative System Check / Automatic Mode.
  7. After the "Evaporative System Check" is completed, check All Readiness by entering the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  8. Input the DTC: P0455 or P0456.
  9. 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.

  10. 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.

PROCEDURE

1.

GO TO EVAP SYSTEM

(a) Refer to EVAP System (See page ).

NEXT

END

    Evaporative Emission Control System Pressure Sensor Range / Performance (P0451-P0453)

    Vehicle Speed Sensor (P0500)

    See More:

    Toyota Tundra Service Manual > Sfi System: Bank 1 Air-Fuel Ratio Imbalance (P219A-P219F,P21A0-P21A3)
    DESCRIPTION Refer to DTC P0300 (See page ). Refer to DTC P2195 (See page ). Refer to DTC P2197 (See page ). DTC No. DTC Detection Condition Trouble Area P219A The difference in air fuel ratios between the cylinders exceeds the threshold (2 trip detection logic). Fuel injector assembly Intake system ...

    Toyota Tundra Owners Manual

    Toyota Tundra Service Manual

    © 2020 Copyright www.ttundra.com
    0.019