DTC    P2420    Evaporative Emission System Switching Valve Control Circuit High

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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:
  1. EVAP pressure change when vent valve closed (ON) less than 0.3 kPa-g (2.25 mmHg-g)
  1. Canister pump module (Reference orifice, leak detection pump, vent valve)
  2. Connector/wire harness (Canister pump module - ECM)
  3. 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 (Click here).

INSPECTION PROCEDURE

Refer to the EVAP System (Click here).

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.
60 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.

A112612E14

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.

A106067E46


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 111 kPa-a (525 to 833 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 (Click here).

CONFIRMATION DRIVING PATTERN


A199236E01

NOTICE:
  1. The Evaporative System Check (Automatic Mode) consists of 6 steps performed automatically by Techstream. It takes a maximum of the approximately 18 minutes.
  2. 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.
  3. Do not run the engine during this operation.
  4. 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
    1. DTC judgment completed
    2. System normal
    ABNORMAL
    1. DTC judgment completed
    2. System abnormal
    INCOMPLETE
    1. DTC judgment not completed
    2. Perform driving pattern after confirming DTC enabling conditions
    N/A
    1. Unable to perform DTC judgment
    2. 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 (Click here).

    HINT:
    1. If a permanent DTC is output, the system is malfunctioning.
    2. If no permanent DTC is output, the system is normal.