2001 TOYOTA SEQUOIA fuel

± DIAGNOSTICSENGINE
DI±273
467 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0455 Evaporative Emission Control System Leak
Detected (Gross Leak)
DTC P0456 Evaporative Emission Control System Leak
Detected (Very Small Leak)
DTC SUMMARY
DTCMonitoring ItemsMalfunction Detection ConditionsTrouble AreasDetection
TimingsDetection
Logic
P0455EVAP gross leak
Vacuum pump creates negative pressure
(vacuum) in EVAP system and EVAP sys-
tem pressure measured. 0.02 inch leak
pressure standard is measured at the start
and at the end of the leak check.
If stabilized pressure higher than [second
0.02 inch leak pressure standard x 0.2],
ECM determines that EVAP system has
large leakage.
Fuel tank cap (loose)

Leakage from EVAP line
(Canister ± Fuel tank)

Leakage from EVAP line
(Purge VSV ± Canister)

Pump module

Leakage from fuel tank

Leakage from canister
While
ignition
switch
OFF
2 trip
P0456EVAP small leak
Vacuum pump creates negative pressure
(vacuum) in EVAP system and EVAP sys-
tem pressure measured. 0.02 inch leak
pressure standard is measured at the start
and at the end of the leak check.
If stabilized pressure larger than second
0.02 inch leak pressure, ECM determines
that EVAP system has small leakage.
Same above
While
ignition
switch
OFF
2 trip
CIRCUIT DESCRIPTION
The circuit description can be found in the EVAP (Evaporative Emission) Inspection Procedure (see page
DI±460).
DID8A±01

B17399
Fuel Tank Canister
Vacuum Pump: OFF Pressure Sensor 0.02 Inch Orifice
Pump Module
Operation A: Atmospheric Pressure Measurement
Vent Valve: OFF (vent)
Operation D: Purge VSV monitor Operation B: 0.02 Inch Leak Pressure Measurement
Negative
Pressure Atmospheric
Pressure
Operation C: EVAP Leak Check
Air Filter
Purge VSV: OFFOFF (vent)
ON
OFF
OFF
ON
ON (closed)ON
ON
ON (closed)
DI±274
± DIAGNOSTICSENGINE
468 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR DESCRIPTION
5 hours* after the ignition switch is turned OFF, the electric vacuum pump creates negative pressure (vacu-
um) in the EVAP (Evaporative Emission) system. The ECM monitors for leaks and actuator malfunctions
based on the EVAP pressure.
HINT:
*: If the engine coolant temperature is not below 35C (95F) 5 hours after the ignition switch is turned off,
the monitor check starts 2 hours later. If it is still not below 35C (95F) 7 hours after the ignition switch is
turned off, the monitor check starts 2.5 hours later.
SequenceOperationsDescriptionsDuration
±ECM activationActivated by soak timer, 5 hours (7 or 9.5 hours) after ignition switch turned to OFF.±
AAtmospheric pressure
measurement
Vent valve turned OFF (vent) and EVAP system pressure measured by ECM in order to
register atmospheric pressure.
If EVAP pressure 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 measure-
mentIn order to determine 0.02 inch leak pressure standard, vacuum pump creates negative pres-
sure (vacuum) through 0.02 inch orifice and them ECM checks if vacuum pump and vent
valve operate normally.
60 seconds
CEVAP system pres-
sure 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 the measured value as it will be used in the leak check.
If EVAP pressure does not stabilize within 15 minutes, ECM cancels EVAP system monitor.
15 minutes*
DPurge VSV monitorPurge VSV opened and then EVAP system pressure measured by ECM.
Large increase indicates normal.10 seconds
E
Second 0.02 inch leak
pressure measure-
mentLeak check is performed after second 0.02 inch leak pressure standard is measured.
If stabilized system pressure higher than second 0.02 inch leak pressure standard, ECM
determines that EVAP system leaking.
60 seconds
FFinal checkAtmospheric 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.

A23486
Purge VSV
Vent Valve
Vacuum Pump
EVAP Pressure
Positive
Leak Pressure
sec NegativeONON
Sequence
TimeA
10
sec60
Within 15 minutes
sec ON
First 0.02 inch
BCD
P0455
ON: Open
OFF: Closed
OFF: Vent ON: Closed
10
Standard
sec60
E
P0456
OK
EVAP Pressure when EVAP system Leaks:
Leak PressureSecond 0.02 inch
Standard x 0.2
± DIAGNOSTICSENGINE
DI±275
469 Author: Date:
2005 SEQUOIA (RM1146U)
(a) P0455: EVAP (Evaporative Emission) gross leak
In operation C, the vacuum pump creates negative pressure (vacuum) in the EVAP system and the EVAP
system pressure is measured. If the stabilized system pressure is higher than [second 0.02 inch leak pres-
sure standard x 0.2] (near atmospheric pressure), the ECM determines that the EVAP system has a large
leakage, illuminates the MIL and sets the DTC (2 trip detection logic).
(b) P0456: EVAP very small leak
In operation C, the vacuum pump creates negative pressure (vacuum) in the EVAP system and the EVAP
system pressure is measured. If the stabilized system pressure is higher than second 0.02 inch leak pres-
sure standard, the ECM determines that the EVAP system has a small leakage, illuminates the MIL and sets
the DTC (2 trip detection logic).
MONITOR STRATEGY
RltdDTCP0455Gross leak detectedRelated DTCsP0456Very small leak (0.020 inch hole) detected
Required sensors/componentsPurge VSV, Pump module
Frequency of operationOnce per driving cycles
DurationWithin 15 min. (varies with amount of fuel in tank)
MIL operation2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee 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:±

DI±280
± DIAGNOSTICSENGINE
474 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions when
a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was
running or stopped, if the engine was warmed up or not, if the air±fuel ratio was lean or rich, as well as other
data from the time when a malfunction occurred.
1 Check operation of speedometer.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch to ON and push the hand±held tester main switch ON.
(c) Start the engine.
(d) When using hand±held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DATA
LIST / PRIMARY / VEHICLE SPD.
CHECK:
Read the mass air flow rate on the hand±held tester.
RESULT:
Vehicle speedProceed to
Vehicle speed remains 0 km/h (0 mph)A
Vehicle speed is lower than actual speedA
Vehicle speed is same as actual speedB
B Check for intermittent problems
(See page DI±11).
A

± DIAGNOSTICSENGINE
DI±285
479 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions when
a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was
running or stopped, if the engine was warmed up or not, if the air±fuel ratio was lean or rich, as well as other
data from the time when a malfunction occurred.
1 Check operation of stop light.
CHECK:
Check if the stop lights come on and go off normally when the brake pedal is operated and released.
NG Check and repair stop light circuit.
OK
2 Check stop light switch (See page BE±47).
NG Replace stop light switch.
OK

DI±290
± DIAGNOSTICSENGINE
484 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:

When the throttle position is slightly opened (the accelerator pedal is slightly depressed) because a
floor carpet is overlapped on the accelerator pedal, or if the accelerator pedal is not fully released, etc.,
DTC P0505 will possibly be detected.

Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions
when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the
vehicle was running or stopped, if the engine was warmed up or not, if the air±fuel ratio was lean or
rich, as well as other data from the time when a malfunction occurred.
1 Are there any other codes (besides P0505) being output?
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand±held tester main switch ON.
(c) When using hand±held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DTC
INFO / CURRENT CODES.
CHECK:
Read the DTC using the hand±held tester.
RESULT:
Display (DTC Output)Proceed to
P0505A
ºP0505º and other DTCsB
HINT:
If any other codes besides P0505 are output, perform the troubleshooting for those DTCs first.
B Go to relevant DTC chart (See page DI±58).
A
2 Check connection of PCV piping.
NG Repair or replace PCV piping.
OK

DI±292
± DIAGNOSTICSENGINE
486 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0560 System Voltage
MONITOR DESCRIPTION
The battery supplies electricity to the ECM even when the ignition switch is OFF. This electricity allows the
ECM to store data such as DTC history, freeze frame data, fuel trim values, and other data.
If the battery voltage falls below a minimum level, the ECM will conclude that there is a fault in the power
supply circuit. The next time the engine starts, the ECM will turn on the MIL and a DTC will be set.
DTC No.DTC Detecting ConditionTrouble Area
P0560Open in back up power source circuit

Open in back±up power source circuit

EFI fuse

ECM
HINT:
If DTC P0560 present, the ECM will not store another DTC.
MONITOR STRATEGY
Related DTCsP0560System voltage malfunction
Required sensors/componentsECM
Frequency of operationContinuous
Duration3 sec.
MIL operationImmediate (*1)
Sequence of operationNone
*1: The DTC is set immediate. The MIL will be illuminated after the engine starts in the next time.
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Stand±by RAMInitialized
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Battery voltageLess than 3.5 V
DICF7±02

A05652A18100
Battery2DEFI No. 1
B±Y
E4ECM
BATT 73
2H 1
IA411
B±Y B
F10
Fusible Link
Block 4Engine Room J/B
5
B12
± DIAGNOSTICSENGINE
DI±293
487 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions when
a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was
running or stopped, if the engine was warmed up or not, if the air±fuel ratio was lean or rich, as well as other
data from the time when a malfunction occurred.
1 Check battery voltage.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch to ON.
(c) Select the item: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / BATTERY VOLTAGE.
CHECK:
Read the battery voltage on the hand±held tester
RESULT:
Battery voltageProceed to
0 VA
Except 0 VB
B Go to step 5.
A