Brand:

Toyota

Model Name:

4Runner GRN210 215 UZN210 215

Manual:

Repair Manual

Section:

1Gr-Fe Engine Control System

Title:

Sfi System

  1. Dtc summary

  2. Description

  3. Inspection procedure

  4. Monitor description

  5. Monitor strategy

  6. Typical enabling conditions

  7. Typical malfunction thresholds

  8. Monitor result

DTC P2401 Evaporative Emission System Leak Detection Pump Control Circuit Low

DTC P2402 Evaporative Emission System Leak Detection Pump Control Circuit High


​

DTC SUMMARY


DTCs
Monitoring Items
Malfunction Detection Conditions
Trouble Areas
Detection Timings
Detection Logic
P2401
Vacuum pump stuck OFF
Vacuum pump creates negative pressure through 0.02 inch orifice, and EVAP system pressure is measured to determine leak pressure standard. The 0.02 inch leak pressure standard is measured at the start and end of the leak check.
If system pressure is higher than -1.06 kPa (-7.95 mmHg)*, or lower than -4.85 kPa (-36.38 mmHg)*, ECM determines that vacuum pump stuck OFF.
  1. Pump module
  2. Connector/wire harness (Pump module - ECM)
  3. ECM
  4. Leakage from EVAP system
While ignition switch off
2 trip
P2402
Vacuum pump stuck ON
Vacuum pump creates negative pressure through 0.02 inch orifice, and EVAP system pressure is measured to determine leak pressure standard.
If system pressure is higher than -1.06 kPa (-7.95 mmHg)*, or lower than -4.85 kPa (-36.38 mmHg)*, ECM determines that vacuum pump stuck ON.
  1. Pump module
  2. Connector/wire harness (Pump module - ECM)
  3. ECM
While ignition switch off
2 trip
*: The threshold values vary according to the atmospheric pressure measured in operation A. The values described in the table above are based on an atmospheric pressure of 100 kPa (750.1 mmHg).
HINT:
The vacuum pump is built into the pump module.

DESCRIPTION

The circuit 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*1 after the ignition switch is turned off, the electric vacuum pump creates negative pressure (vacuum) in the EVAP (Evaporative Emission) system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.

HINT:
*1: If the engine coolant temperature is not below 35°C (95°F) after 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
Operations
Descriptions
Duration
-
ECM activation
Activated by soak timer, 5 hours (7 or 9.5 hours) after ignition switch turned to 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 is not between 70 kPa and 110 kPa (525 mmHg and 825 mmHg), ECM cancels EVAP system monitor.
10 seconds
B
First 0.02 inch leak pressure measurement
In order to determine 0.02 inch leak pressure standard, vacuum pump creates negative pressure (vacuum) through 0.02 inch orifice and then ECM checks if vacuum 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) is 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*2
D
Purge VSV monitor
Purge VSV is opened and then EVAP system pressure is measured by ECM.
Large increase indicates normal.
10 seconds
E
Second 0.02 inch leak pressure measurement
After second 0.02 inch leak pressure measurement, leak check is performed by comparing first and second 0.02 inch leak pressure standards.
If stabilized system pressure is higher than second 0.02 inch leak pressure standard, ECM determines that EVAP system leaking.
60 seconds
F
Final check
Atmospheric pressure is measured and then monitoring result is recorded by ECM.
-
*2: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.

P2401: Vacuum pump stuck OFFIn operation B, the vacuum pump creates negative pressure (a vacuum) through the 0.02 inch orifice. The EVAP (Evaporative Emission) system pressure is then measured by the ECM, using the pressure sensor, to determine the 0.02 inch leak pressure standard. If the pressure is higher than -1.06 kPa (-7.95 mmHg)*, or lower than -4.85 kPa (-36.38 mmHg)*, the ECM interprets this as the vacuum pump being stuck OFF (not operating). The ECM illuminates the MIL and sets the DTC (2 trip detection logic).*: The thresholds vary according to the atmospheric pressure measured in operation A. The values described above are based on an atmospheric pressure of 100 kPa (750.1 mmHg): absolute pressure. 4Runner

  1. P2401: Vacuum pump stuck OFF
    In operation B, the vacuum pump creates negative pressure (a vacuum) through the 0.02 inch orifice. The EVAP (Evaporative Emission) system pressure is then measured by the ECM, using the pressure sensor, to determine the 0.02 inch leak pressure standard. If the pressure is higher than -1.06 kPa (-7.95 mmHg)*, or lower than -4.85 kPa (-36.38 mmHg)*, the ECM interprets this as the vacuum pump being stuck OFF (not operating). The ECM illuminates the MIL and sets the DTC (2 trip detection logic).
    *: The thresholds vary according to the atmospheric pressure measured in operation A. The values described above are based on an atmospheric pressure of 100 kPa (750.1 mmHg): absolute pressure.


    P2402: Vacuum pump stuck ONIn operation B, the vacuum pump creates negative pressure (a vacuum) through the 0.02 inch orifice. The EVAP (Evaporative Emission) system pressure is then measured by the ECM, using the pressure sensor, to determine the 0.02 inch leak pressure standard. If the pressure is higher than -1.06 kPa (-7.95 mmHg)*, or lower than -4.85 kPa (-36.38 mmHg)*, the ECM interprets this as the vacuum pump being stuck ON (remaining ON all the time). The ECM illuminates the MIL and sets the DTC (2 trip detection logic).*: The thresholds vary according to the atmospheric pressure measured in operation A. The values described above are based on an atmospheric pressure of 100 kPa (750.1 mmHg): absolute pressure.HINT: The detection logic of DTCs P2401 and P2402 is the same because in both cases the 0.02 inch leak pressure standard measured in operation B is compared to the atmospheric pressure registered in operation A. The ECM calculates the difference between these pressures by deducting [the 0.02 inch leak pressure standard] from [the stored atmospheric pressure], and uses this to monitor the EVAP system pressure change. 4Runner

  2. P2402: Vacuum pump stuck ON
    In operation B, the vacuum pump creates negative pressure (a vacuum) through the 0.02 inch orifice. The EVAP (Evaporative Emission) system pressure is then measured by the ECM, using the pressure sensor, to determine the 0.02 inch leak pressure standard. If the pressure is higher than -1.06 kPa (-7.95 mmHg)*, or lower than -4.85 kPa (-36.38 mmHg)*, the ECM interprets this as the vacuum pump being stuck ON (remaining ON all the time). The ECM illuminates the MIL and sets the DTC (2 trip detection logic).
    *: The thresholds vary according to the atmospheric pressure measured in operation A. The values described above are based on an atmospheric pressure of 100 kPa (750.1 mmHg): absolute pressure.


    1. Atmospheric pressure measurement Next sequence is run if the following condition is set-Atmospheric pressure changeLess than 0.3 kPa (2.25 mmHg) in 1 second2. First reference pressure measurement Next sequence is run if the following conditions are set-EVAP pressure just after reference pressure measurement start-1 kPa (-7.5 mmHg) or lessReference pressure-4.85 to -1.057 kPa (-36.38 to -7.93 mmHg)Reference pressureSaturated3. EVAP canister vent valve close stuck check Next sequence is run if the following condition is set-EVAP pressure change after vent valve is ON0.3 kPa (2.25 mmHg) or more4. Vacuum introduction Next sequence is run if the following condition is set-EVAP pressureSaturated within 12 minutes5. EVAP canister purge valve close stuck check Next sequence is run if the following condition is set-EVAP pressure change after purge valve is open0.3 kPa (2.25 mmHg) or more6. Second reference pressure measurement Next sequence is run if the following conditions are set-EVAP pressure just after reference pressure measurement start-1 kPa (-7.5 mmHg) or lessReference pressure-4.85 to -1.057 kPa (-36.384 to -7.929 mmHg)Reference pressureSaturatedDifference between first reference pressure and second reference pressureLess than 0.7 kPa (5.25 mmHg)7. Leak check Next sequence is run if the following condition is set-EVAP pressure when vacuum introduction is completeLower than second reference pressure8. Atmospheric pressure measurement EVAP monitor is complete if the following condition is set-Atmospheric pressure difference between sequence 1 and 8Within 0.3 kPa (2.25 mmHg) 4Runner

    HINT:
    The detection logic of DTCs P2401 and P2402 is the same because in both cases the 0.02 inch leak pressure standard measured in operation B is compared to the atmospheric pressure registered in operation A. The ECM calculates the difference between these pressures by deducting [the 0.02 inch leak pressure standard] from [the stored atmospheric pressure], and uses this to monitor the EVAP system pressure change.

MONITOR STRATEGY


Related DTCs
P2401: Vacuum pump stuck OFF
P2402: Vacuum pump stuck ON
Required Sensors / Components
Pump module
Frequency of Operation
Once per driving cycle
Duration
Within 2 minutes
MIL Operation
2 driving cycles
Sequence of Operation
None

TYPICAL ENABLING CONDITIONS


The monitor will run whenever these DTCs are not present
None
Atmospheric pressure
70 to 110 kPa (525 to 825 mmHg)
Battery voltage
10.5 V or more
Vehicle speed
Less than 2.5 mph (4km/h)
Ignition switch
OFF
Time after key off
5 or 7 or 9.5 hours
EVAP pressure sensor malfunction (P0450, P0452, P0453)
Not detected
EVAP canister purge valve
Not operated by scan tool
EVAP canister vent valve
Not operated by scan tool
EVAP leak detection pump
Not operated by scan tool
Both of the following conditions are met before key off
Condition 1 or 2
1. Duration that vehicle has been 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)
Key-off monitor sequence 1 to 8

  1. 1. Atmospheric pressure measurement
    Next sequence is run if the following condition is set
    		-
    Atmospheric pressure change
    		Less than 0.3 kPa (2.25 mmHg) in 1 second

    2. First reference pressure measurement
    Next sequence is run if the following conditions are set
    		-
    EVAP pressure just after reference pressure measurement start
    		-1 kPa (-7.5 mmHg) or less
    Reference pressure
    		-4.85 to -1.057 kPa (-36.38 to -7.93 mmHg)
    Reference pressure
    		Saturated

    3. EVAP canister vent valve close stuck check
    Next sequence is run if the following condition is set
    		-
    EVAP pressure change after vent valve is ON
    		0.3 kPa (2.25 mmHg) or more

    4. Vacuum introduction
    Next sequence is run if the following condition is set
    		-
    EVAP pressure
    		Saturated within 12 minutes

    5. EVAP canister purge valve close stuck check
    Next sequence is run if the following condition is set
    		-
    EVAP pressure change after purge valve is open
    		0.3 kPa (2.25 mmHg) or more

    6. Second reference pressure measurement
    Next sequence is run if the following conditions are set
    		-
    EVAP pressure just after reference pressure measurement start
    		-1 kPa (-7.5 mmHg) or less
    Reference pressure
    		-4.85 to -1.057 kPa (-36.384 to -7.929 mmHg)
    Reference pressure
    		Saturated
    Difference between first reference pressure and second reference pressure
    		Less than 0.7 kPa (5.25 mmHg)

    7. Leak check
    Next sequence is run if the following condition is set
    		-
    EVAP pressure when vacuum introduction is complete
    		Lower than second reference pressure

    8. Atmospheric pressure measurement
    EVAP monitor is complete if the following condition is set
    		-
    Atmospheric pressure difference between sequence 1 and 8
    		Within 0.3 kPa (2.25 mmHg)

TYPICAL MALFUNCTION THRESHOLDS


One of the following conditions is met
Condition 1, 2, 3, 4 or 5
1. EVAP pressure just after reference pressure measurement start
More than -1 kPa (-7.5 mmHg)
2. Reference pressure
Less than -4.85 kPa (-36.38 mmHg)
3. Reference pressure
-1.057 kPa (-7.93 mmHg) or more
4. Reference pressure
Not saturated
5. Difference between first reference pressure and second reference pressure
0.7 kPa (5.25 mmHg)

MONITOR RESULT

Refer to Monitor Result for detailed information (Click here).