Toyota Tundra Service Manual: Evaporative Emission Pressure Switching Valve Stuck OFF (P2420)

Toyota Tundra Service Manual / Engine, Hybrid System / 1ur-fe Engine Control / Sfi System / Evaporative Emission Pressure Switching Valve Stuck OFF (P2420)

DTC SUMMARY

DTC No.

Monitoring Item

Malfunction Detection Condition

Trouble Area

Detection Timing

Detection Logic

P2420

Vent valve stuck open (vent)

Following condition met during key-off EVAP monitor:

  • EVAP pressure change when vent valve closed (ON) less than 0.3 kPa-g (2.25 mmHg-g)
  • Canister pump module (Reference orifice, leak detection pump, vent valve)
  • Connector/wire harness (Canister pump module - ECM)
  • ECM

While ignition switch off

2 trip

HINT:

The vent valve is built into the canister pump module.

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 37.5°C (99.5°F) 5 hours after the ignition switch is turned off, the monitor check starts 2 hours later. If it is still not below 37.5°C (99.5°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.

P2420: Vent valve stuck open (vent)

In operation C, the vent valve turns ON (closes) and the EVAP system pressure is then measured by the ECM using the canister pressure sensor to conduct an EVAP leak check. If the pressure does not increase when the vent valve is open, the ECM interprets this as the vent valve being stuck open. The ECM illuminates the MIL and stores the DTC.

MONITOR STRATEGY

Required Sensors/Components

Purge VSV and canister pump module

Frequency of Operation

Once per driving cycle

Duration

Within 7 minutes (varies with amount of fuel in tank)

MIL Operation

2 driving cycles

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever following DTCs not present

P0452, P0453 (EVAP system)

EVAP key-off monitor runs when all of following conditions met

-

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)

TYPICAL MALFUNCTION THRESHOLDS

EVAP pressure change after EVAP canister vent valve ON

Less than 0.3 kPa-g (2.25 mmHg-g)

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 Techstream. It takes a maximum of the 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 [A].
  6. Enter the following menu items: 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: P2420.
  9. Check the DTC judgment result [B].

    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

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