Toyota Sequoia (2005). Manual - part 168

–

DIAGNOSTICS

ENGINE

DI–467

661

2

Perform EVAP system check.

NOTICE:

In the EVAP SYSTEM CHECK (AUTO OPERATION), the series of 5 EVAP SYSTEM CHECK steps
is performed automatically. It takes a maximum of approximately 18 minutes.

Do not perform the EVAP SYSTEM CHECK when the fuel tank is more than 90% full because
the cut–off valve may be closed and making the leak check of the fuel tank unavailable.

Do not run the engine in this step.

When the temperature of the fuel is 35



C

 

(95



F) or more, a large amount of vapor forms and any

check results become inaccurate. When performing the EVAP SYSTEM CHECK, keep the tem-
perature below 35



C

 

(95



F).

(a)

Clear DTCs (see page 

DI–43

).

(b)

On the hand–held tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / SYS-
TEM CHECK / EVAP SYS CHECK / AUTO OPERATION.

(c)

After the EVAP SYSTEM CHECK is completed, check for pending DTCs by selecting the following
menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / PENDING CODES.

HINT:
If no pending DTC is displayed, perform the Monitor Confirmation after this repair is completed. After this
confirmation, check for pending DTCs. If no DTC is displayed, the EVAP system is normal.

NEXT

A23497

Purge VSV

Vent Valve

Vacuum Pump

EVAP Pressure

Positive

Leak Pressure

ON: Open

Negative

ON

ON

Steps

(Reference)

60

Within 15 minutes

10

60

ON

First 0.02 inch

2/5

3/5

4/5

5/5

OFF: Closed

OFF: Vent

ON: Closed

EVAP SYSTEM CHECK

sec

sec

sec

Normal Pressure

10

sec

1/5

Gross Leak

No Leak

Small Leak

Time

Leak Pressure

Second 0.02 inch

Standard

Standard x 0.2

DI–468

–

DIAGNOSTICS

ENGINE

662

3

Perform EVAP system manual operation check.

NOTICE:

In the EVAP SYSTEM CHECK (MANUAL OPERATION), the series of 5 EVAP SYSTEM CHECK
steps is performed manually.

Do not perform the EVAP SYSTEM CHECK when the fuel tank is more than 90% full because
the cut–off valve may be closed and making the leak check of the fuel tank unavailable.

Do not run the engine in this step.

When the temperature of the fuel is 35



C

 

(95



F) or more, a large amount of vapor forms and any

check results become inaccurate. When performing the EVAP SYSTEM CHECK, keep the tem-
perature below 35



C

 

(95



F).

(a)

Clear DTCs (see page 

DI–43

).

(b)

On the hand–held tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / SYS-
TEM CHECK / EVAP SYS CHECK / MANUAL OPERATION.

NEXT

A23499

Purge VSV

Vent Valve

Vacuum Pump

EVAP Pressure

Positive

ON: Open

Negative

ON

ON

Steps

(Reference)

ON

OFF: Closed

OFF: Vent

ON: Closed

10

sec

1/5

Time

Pressure Sensor Noising

OK

Leak Pressure

First 0.02 inch

Standard

–

DIAGNOSTICS

ENGINE

DI–469

663

4

Perform EVAP system step 1/5 check.

(a)

Check the EVAP pressure in step 1/5.
Result:

DTCs*

Test Results

Suspected Trouble Areas

Proceed To



Virtually no variation in EVAP pressure

Not yet determined

A

P0451

EVAP pressure fluctuates by 

0.3 kPa 

(2.25 mmHg) or more

Pressure sensor noising

B

*: The DTCs relating to the EVAP system displayed on a hand–held tester when checking.

B

Go to step 30

A

A23500

Purge VSV

Vent Valve

Vacuum Pump

EVAP Pressure

Positive

ON: Open

Negative

ON

ON

Steps

(Reference)

ON

OFF: Closed

OFF: Vent

ON: Closed

10

sec

1/5

Time

Vacuum Pump Stuck ON

60

sec

2/5

Leak Pressure

First 0.02 inch

Standard

DI–470

–

DIAGNOSTICS

ENGINE

664

5

Perform EVAP system step 1/5 to 2/5 check.

(a)

Check the EVAP pressure in step 1/5 and 2/5.
Result:

DTCs*

Test Results

Suspected Trouble Areas

Proceed To



Virtually no variation in EVAP pressure during step
1/5. Then decreases to 0.02 inch leak pressure
standard*

Not yet determined

A

P2402

Small difference between EVAP pressures during
steps 1/5 and 2/5

Vacuum pump stuck ON

B

*: The DTCs relating to the EVAP system displayed on a hand–held tester when checking.
HINT:
The 0.02 inch leak pressure standard is the value determined in step 2/5.

B

Go to step 23.

A