2001 TOYOTA SEQUOIA check engine

A23494
Pump Module (fig. 1):
Condition: Purge FlowCondition: Leak Check
From Refueling Valve
To Air Filter
(Atmosphere)
Vacuum Pump: OFFVent Valve: OFF
(vent)
Pressure Sensor 0.02 Inch Orifice
Canister
: Airflow
Vacuum Pump: ON
Vent Valve: ON
(closed)
A23495
Pressure Sensor Specification (fig. 2)
Output Voltage
Usable Range
4.900 V
4.150 V
1.425 V
0.450 V
Malfunction Area
Pressure
60
kPa11 0
kPa
Malfunction Area
Standard atmospheric pressure is 101.3 kPaHINT:
A23496
Soak Timer Circuit (fig. 3)
Ignition Switch
IGSW
Power
ECM
EFI MAIN
MREL+B
15 ASource IC
Soak Timer IC Main Relay
Control IC
Battery DI±464
± DIAGNOSTICSENGINE
658 Author: Date:
2005 SEQUOIA (RM1146U)

0.02 inch orifice clogged
Pressure sensor voltage lowP043E
P043FP0441 P0451 P0452 P0453 P0455 P0456 P2419P2401
P2402
0.02 inch orifice high±flow
Pressure sensor stuck
Pressure sensor noising
Gross leak
Small leak
Vacuum pump stuck OFF
Vacuum pump stuck ON
Vent valve stuck ON (closed)
Vent valve stuck OFF (vent) Purge VSV stuck open
Purge VSV stuck closed
Pressure sensor voltage high
DTCs
Malfunctioning AreasP2420P0450
DI±466
± DIAGNOSTICSENGINE
660 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
NOTICE:
A hand±held tester is required to conduct the following diagnostic troubleshooting procedure.
HINT:

Using hand±held tester monitor results enables the EVAP (Evaporative Emission) system to be con-
firmed.

Read freeze frame data using a hand±held tester Freeze frame data record the engine condition when
malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle
was moving or stationary, if the engine was warmed up or not, if the air±fuel ratio was lean or rich, and
other data, from the time the malfunction occurred.
1 Confirm DTC.
(a) Turn the ignition switch to OFF and wait for 10 seconds.
(b) Turn the ignition switch to ON.
(c) Turn the ignition switch to OFF and wait for 10 seconds.
(d) Connect a hand±held tester to the DLC3.
(e) Turn the ignition switch to ON and turn the tester ON.
(f) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
(g) Confirm DTCs and freeze frame data.
If any EVAP system DTCs are set, the malfunctioning area can be determined using the table below.
NOTICE:
If the 0.02 inch reference pressure difference between the first and second checks is greater than
the specification, the DTCs corresponding to the reference pressure (P043E, P043F, P0441, P0455,
P0456, P2401, P2420) will be all stored.
NEXT

± DIAGNOSTICSENGINE
DI±467
661 Author: Date:
2005 SEQUOIA (RM1146U)
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 35C (95F) 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 35C
(95F).
(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 PressureON: Open
NegativeONON
Steps
(Reference)60 Within 15 minutes 10 60ON
First 0.02 inch
2/5 3/5 4/55/5
OFF: Closed
OFF: Vent ON: Closed
EVAP SYSTEM CHECK
sec sec sec
Normal Pressure
10
sec
1/5
Gross Leak
No Leak Small Leak
TimeLeak Pressure
Second 0.02 inch
StandardStandard x 0.2
DI±468
± DIAGNOSTICSENGINE
662 Author: Date:
2005 SEQUOIA (RM1146U)
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 35C (95F) 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 35C
(95F).
(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
NegativeONON
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
± DIAGNOSTICSENGINE
DI±469
663 Author: Date:
2005 SEQUOIA (RM1146U)
4 Perform EVAP system step 1/5 check.
(a) Check the EVAP pressure in step 1/5.
Result:
DTCs*Test ResultsSuspected Trouble AreasProceed To
'Virtually no variation in EVAP pressureNot yet determinedA
P0451EVAP pressure fluctuates by
0.3 kPa
(2.25 mmHg) or morePressure sensor noisingB
*: 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
NegativeONON
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
± DIAGNOSTICSENGINE
664 Author: Date:
2005 SEQUOIA (RM1146U)
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 ResultsSuspected Trouble AreasProceed To
'
Virtually no variation in EVAP pressure during step
1/5. Then decreases to 0.02 inch leak pressure
standard*
Not yet determinedA
P2402Small difference between EVAP pressures during
steps 1/5 and 2/5Vacuum pump stuck ONB
*: 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

A23501
ON
Within 15 minutes
2/5
0.02 inch Orifice High±flow
Vent Valve Stuck closed
OK
0.02 inch Orifice Clogged
60
sec
3/5
4 sec
Vacuum Pump Stuck OFF
ONON
Purge VSV
Vent Valve
Vacuum Pump
EVAP Pressure
Positive
Negative
Steps
(Reference)TimeON: Open
OFF: Closed
OFF: Vent ON: Closed
Leak Pressure First 0.02 inch
Standard
± DIAGNOSTICSENGINE
DI±471
665 Author: Date:
2005 SEQUOIA (RM1146U)
6 Perform EVAP system step 2/5 check.
HINT:
Make a note of the pressures checked in steps (a) and (b) below.
(a) Check the EVAP pressure 4 seconds after the vacuum pump is activated*.
(b) Check the EVAP pressure again when it has stabilized. This pressure is the 0.02 inch leak pressure
standard.
*: The vacuum pump begins to operate as step 1/5 is proceeded to step 2/5.
Result:
DTCs*Test ResultsSuspected Trouble AreasProceed To
'EVAP pressure in step (b) between ±4.85 kPa
and ±1.06 kPa (±36.38 mmHg and ±7.95 mmHg)Not yet determinedA
P043F and P2401EVAP pressure in step (b) ±1.06 kPa (±7.95
mmHg) or more
0.02 inch orifice high±flow

Vacuum pump stuck OFFB
P043EEVAP pressure in step (b) below ±4.85 kPa
(±36.38 mmHg)0.02 inch orifice cloggedC
P2419EVAP pressure in step (a) more than ±1.06 kPa
(±7.95 mmHg)Vent valve stuck closedD
*: The DTCs relating to the EVAP system displayed on a hand±held tester when checking.
B Go to step 11
C Go to step 30
D Go to step 19
A

A23502
ON
Within 15 minutes
2/5
Vent Valve Stuck open (vent)
3/5
ONON
Purge VSV
Vent Valve
Vacuum Pump
EVAP Pressure
Positive
Negative
Steps
(Reference)TimeON: Open
OFF: Closed
OFF: Vent ON: Closed
Leak Pressure First 0.02 inch
Standard
DI±472
± DIAGNOSTICSENGINE
666 Author: Date:
2005 SEQUOIA (RM1146U)
7 Perform EVAP system step 2/5 to 3/5 check.
(a) Check the EVAP pressure increase in step 3/5.
Result:
DTCs*Test ResultsSuspected Trouble AreasProceed To
'
EVAP pressure increases by 0.3 kPa (2.25 mmHg)
or more within 10 seconds of proceeding from step
2/5 to step 3/5
Not yet determinedA
P2420No variation in EVAP pressure despite proceeding
from step 2/5 to step 3/5Vent valve stuck open (vent)B
P0451No variation in EVAP pressure during steps 1/5
through 3/5Pressure sensor malfunction stuckC
*: The DTCs relating to the EVAP system displayed on a hand±held tester when checking.
B Go to step 19.
C Go to step 30.
A