Toyota Sequoia (2005). Manual - part 156

A23666

Purge VSV

Vent Valve

Vacuum Pump

EVAP Pressure

Positive

Leak Pressure

sec

Negative

ON

ON

Sequence

Time

A

10

sec

60

Within 15 minutes

ON

First 0.02 inch

B

C

D

EVAP Pressure when Vent Valve Stuck OFF (vent):

OK

Malfunction

ON: Open
OFF: Closed

OFF: Vent

ON: Closed

10

Standard

sec

60

E

–

DIAGNOSTICS

ENGINE

DI–419

613

(b)

P2420: Vent valve stuck open (vent)

In operation C, the vent valve turns ON (closes) and the EVAP (Evaporative Emission) system pressure is
then measured by the ECM, using the 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 sets the DTC.

MONITOR STRATEGY

R l t d DTC

P2419

Vent valve stuck open

Related DTCs

P2420

Vent valve stuck closed

Required sensors/components

Vent valve

Frequency of operation

Once per driving cycle

Duration

8 sec. (P2419), 10 sec. (P2420)

MIL operation

2 driving cycles

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

It

Specification

Item

Minimum

Maximum

The monitor will run whenever these

DTCs are not present

See page 

DI–18

Following values are when atmospheric is

760 mmHg (100 kPa)

–

EVAP key–off monitor runs when all of the

following conditions met:

–

Atmospheric pressure

525 to 825 mmHg (70 to 110 kPa)

Battery voltage

10.5 V

–

Vehicle speed

–

4 km/h (2.5 mph)

Ignition switch

OFF

Engine condition

Not running

Time after engine stopped

5 hours

DI–420

–

DIAGNOSTICS

ENGINE

614

FTP sensor malfunction (P0450, P0452,

P0453)

Not detected

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 are met

before IG switch OFF

Condition 1 and 2

1. Duration that vehicle is driven

5 min.

–

2. Purge flow

Executed

ECT

4.4 to 35

°

C (40 to 95

°

F)

IAT

4.4 to 35

°

C (40 to 95

°

F)

Example of re–start time

–

First time

7 hours

Second time

9 hours and 30 min.

Key–off monitor sequence

1 to 8

1. Atmospheric pressure

–

Next sequence is run if following condition

set

–

Atmospheric pressure change for 10 sec.

–

2.25 mmHg (0.3 kPa) for 1 sec.

2. First reference pressure

–

Next sequence is run if all of following

conditions set

Condition 1, 2 and 3

1. FTP when 4 sec. after reference pres-

sure measurement

–

–7.5 mmHg (–1 kPa)

2. Reference pressure

–36.38 to –7.93 mmHg (–4.85 to –1.057 kPa)

3. Reference pressure

Saturated

3. Vent valve stuck closed check

–

Next sequence is run if following condition

set

–

FTP change for 10 sec. after vent valve

ON (closed)

2.25 mmHg (0.3 kPa)

–

4. Vacuum introduction and leak

–

Next sequence is run if both of following

conditions set

Condition 1 and 2

1. Vacuum introduction time

–

15 min.

2. FTP

FTP was saturated

5. Purge VSV stuck closed check

–

Next sequence is run if following condition

set

–

FTP change for 10 sec. after purge VSV

ON (open)

2.25 mmHg (0.3 kPa)

–

6. Second reference pressure measure-

ment

–

Next sequence is run if all of following

conditions set

Condition 1, 2, 3 and 4

1. FTP when 4 sec. after reference pres-

sure measurement

–

–7.5 mmHg (–1 kPa)

2. Reference pressure

–36.38 to –7.93 mmHg (–4.85 to –1.057 kPa)

–

DIAGNOSTICS

ENGINE

DI–421

615

3. Reference pressure

Saturated

4. Reference pressure difference between

first and second

–

5.25 mmHg (0.7 kPa)

7. Leak check

–

Next sequence is run if following condition

set

–

FTP when vacuum introduction was com-

plete

–

Second reference pressure

8. Atmospheric pressure

–

Monitor is complete if following

–

Atmospheric pressure difference between

sequence 1 and 8

–

2.25 mmHg (0.3 kPa)

TYPICAL MALFUNCTION THRESHOLDS

Detection Criteria

Threshold

Vent valve stuck open:

Following valuers are when atmospheric pressure is 760
mmHg (100 kPa)

–

One of the following conditions set

Condition 1, 2, 3, 4 or 5

1. FTP when 4 sec. after reference pressure measurement

began

–7.5 mmHg (–1 kPa) or more

2. Reference pressure

–36.38 mmHg (–4.85 kPa) or less

3. Reference pressure

–7.93 mmHg (–1.057 kPa) or more

4. Reference pressure

Not saturated

5. Reference pressure difference between first and second

More than 5.25 mmHg (0.7 kPa)

Vent valve stuck closed:

FTP change for 10 sec. after vent valve opened

Less than 2.25 mmHg (0.3 kPa)

MONITOR RESULT (MODE 06 DATA)

Refer to page 

DI–26

 for detailed information on Monitor Result.

INSPECTION PROCEDURE

Refer to the EVAP Inspection Procedure (see page 

DI–460

).

A20311

Pressure
Sensor

ECM

VC

AIP

E2

VC

PIM

E2

DI–422

–

DIAGNOSTICS

ENGINE

616

DTC

P2430

Secondary Air Injection System Air Flow/
Pressure Sensor Circuit Bank 1

DTC

P2431

Secondary Air Injection System Air Flow/Pressure
Sensor Circuit Range/Performance Bank 1

DTC

P2432

Secondary Air Injection System Air Flow/
Pressure Sensor Circuit Low Bank 1

DTC

P2433

Secondary Air Injection System Air Flow/
Pressure Sensor Circuit High Bank 1

CIRCUIT DESCRIPTION

Refer to DTC P412 on page 

DI–234

.

DTC No.

DTC Detecting Condition

Trouble Area

P2430

While the engine is running, voltage output of the pressure
sensor indicates 0.1V or less, or indicates 4.8V or more.
(1 trip detection logic)

P2431

The pressure sensor indicates less than 45 kPa (338 mHg), or
more than 135 kPa (1013 mHg).
(1 trip detection logic)

Pressure sensor
O

h t i

i

it

P2432

While the engine is running, voltage output of pressure sensor
remains below 0.1 V.
(1 trip detection logic)

Open or short in pressure sensor circuit

ECM

P2433

While the engine is running, voltage output of the pressure
sensor remains above 4.8 V.
(1 trip detection logic)

MONITOR DESCRIPTION

The ECM observes the pressure in the secondary air passage
using the pressure sensor located on the air switching valve in
the secondary air injection system.
If there is a defect in the sensor or the sensor circuit, the voltage
level will deviate from the normal operating range, the ECM in-
terprets this deviation as a defect in the pressure sensor circuit
and sets a DTC.

DIDMT–01