A23480
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±446
± DIAGNOSTICSENGINE
640 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) after 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 then 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.
A23669
EVAP Purge Flow:
Canister Purge VSV
(ON)
Vacuum Pump (OFF)Air Filter Fuel Tank fuel tank cap
To Intake Manifold
Pump Module
Pressure Sensor0.02 Inch Orifice
Vent Valve (OFF)
ECM
Soak Timer
Refueling Valve
To Atmosphere
DI±462
± DIAGNOSTICSENGINE
656 Author: Date:
2005 SEQUOIA (RM1146U)
Key±off monitor
This monitor checks for EVAP (Evaporative Emission) system leaks and pump module malfunctions. The
monitor starts 5 hours*
after the ignition switch is turned OFF. More than 5 hours are required to allow enough
time for the fuel to cool down to stabilize the Fuel Tank Pressure (FTP), thus making the EVAP system moni-
tor more accurate.
The electric vacuum pump creates negative pressure (vacuum) in the EVAP system and the pressure is
measured. Finally, the ECM monitors for leaks from the EVAP system, and malfunctions in both the pump
module and purge VSV, based on the EVAP pressure.
HINT:
*:If the engine coolant temperature is not below 35C 5 hours after the ignition switch is turned off, the moni-
tor check starts 2 hours later. If it is still not below 35C 7 hours after the ignition switch is turned off, the
monitor check starts 2.5 hours later.
Purge flow monitor
The purge flow monitor consists of the two monitors. The 1st monitor is always conducted every time and
the 2nd monitor is activated if necessary.
The 1st monitor
While the engine is running and the purge VSV (Vacuum Switching Valve) is ON (open), the ECM
monitors the purge flow by measuring the EVAP pressure change. If negative pressure is not
created, the ECM begins the 2nd monitor.
The 2nd monitor
The vent valve is turned ON (closed) and the EVAP pressure is then measured. If the variation
in the pressure is less than 0.5 kpa (3.75 mmHg), the ECM interprets this as the purge VSV being
stuck closed, and illuminates the MIL and sets DTC P0441 (2 trip detection logic).
Atmospheric pressure check:
In order to ensure reliable malfunction detection, the variation between the atmospheric pressures, before
and after conduction of the purge flow monitor, is measured by the ECM.
± DIAGNOSTICSENGINE
DI±463
657 Author: Date:
2005 SEQUOIA (RM1146U)Components
Operations
CanisterContains activated charcoal to absorb EVAP (Evaporative Emissions) generated in fuel tank.
Cut±off valveLocated in fuel tank. Valve floats and closes when fuel tank is 100 % full.
Purge VSV (Vacuum
Switching Valve)Opens or closes line between canister and intake manifold. ECM uses purge VSV to control EVAP purge flow. In order
to discharge EVAP absorbed by canister to intake manifold, ECM opens purge VSV. EVAP discharge volume to intake
manifold controlled by purge VSV duty cycle ratio (current±carrying time). (Open: ON, Close: OFF)
Refueling valve
Controls EVAP pressure from fuel tank to canister. Valve consists of diaphragm, spring and restrictor (diameter: 0.08
inch). When fuel vapor and pressure inside fuel tank increase, valve opens. While EVAP purged, valve closes and re-
strictor prevents large amount of vacuum from affecting pressure in fuel tank. Valve opened while refueling. When valve
open, adding fuel into fuel tank possible.
Roll±over valveLocated in fuel tank. Valve closes by its own weight when vehicle overturns to prevent fuel from spilling out.
Service portUsed for connecting vacuum gauge for inspecting EVAP system.
Soak timerBuilt into ECM. To ensure accurate EVAP monitor, measures 5 hours* after ignition switch turned to OFF. This allows
fuel to cool down, stabilizing Fuel Tank Pressure (FTP). When approx. 5 hours
* elapsed, ECM activates.
Pump moduleConsists of (a) to (d) below. Pump module cannot be disassembled.
(a) Vent valve
Vents and closes EVAP system. When ECM turns valve ON, EVAP system closed. When, ECM turns valve OFF, EVAP
system vented. Negative pressure (vacuum) created in EVAP system to check for EVAP leaks by closing purge VSV,
turning on vent valve (closed) and operating vacuum pump (refer to fig. 1).
(b) Pressure sensorIndicates pressure as voltages. ECM supplies regulated 5 V to pressure sensor, and uses feedback from sensor to
monitor EVAP system pressure (refer to fig 2).
(c) Vacuum pumpCreates negative pressure (vacuum) in EVAP system for leak check.
(d) 0.02 inch orificeHas opening with 0.02 inch diameter. Vacuum produced through orifice by closing purge VSV, turning off vent valve and
operating vacuum pump, to monitor 0.02 inch leak pressure. 0.02 inch leak pressure indicates small leak of EVAP.
HINT:
*:If the engine coolant temperature is not below 35C after 5 hours after the ignition switch is turned off, the
monitor check starts 2 hours later. If it is still not below 35C 7 hours after the ignition switch is turned off,
the monitor check starts 2.5 hours later.
± DIAGNOSTICSENGINE
DI±489
683 Author: Date:
2005 SEQUOIA (RM1146U)
36 Repair or replace parts and components indicated by output DTCs.
(a) Repair the malfunctioning areas indicated by the DTCs that had been confirmed when the vehicle was
brought in.
NEXT Go to step 37.
37 Perform EVAP system auto operation check.
NOTICE:
In the EVAP SYSTEM CHECK (AUTO OPERATION), the series of 4 EVAP SYSTEM CHECK steps
is performed automatically. It takes a maximum of approximately 15 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 an 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 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 found, the repair has been successfully completed.
NEXT
Completed
Monitor Confirmation
HINT:
After a repair, check Monitor Status by performing the Key±Off Monitor Confirmation and Purge Flow Monitor
Confirmation described below.
1. KEY±OFF MONITOR CONFIRMATION
(a) Preconditions
The monitor will not run unless:
The vehicle has been driven for 10 minutes or more (in a city area or on a free way)
The fuel tank is less than 90 % full
The altitude is less than 8,000 ft (2,400 m)
The Engine Coolant Temperature (ECT) is between 4.4C and 35C (40F and 95F)
The Intake Air Temperature (IAT) is between 4.4C and 35C (40F and 95F)
The vehicle remains stationary (the vehicle speed is 0 mph [0 km/h])
DIDIL±01
D14205
Shift Solenoid Valve S1
MIL
(Malfunction Indicator Lamp) S1
S2
SL1
SL2
SLT
SLU
SR
WShift Solenoid Valve S2
Shift Solenoid Valve SL1
Shift Solenoid Valve SL2
Shift Solenoid Valve SLT
Shift Solenoid Valve SLU
Shift Solenoid Valve SR
OILW
AT Oil Temp Warning Light ECM Crankshaft Position Sensor
Engine CoolantTemperature Sensor
Combination Meter
Stop Lamp Switch Assy
DLC3
(Data Link Connector 3)THW VTA1, 2
VC
SPD
STPTH01
TC Throttle Position Sensor
ATF (Automatic Transmission
Fluid) Temperature Sensor No. 1Mass Air Flow Meter
Accelerator Pedal Position SensorVPA
VPA2
Shift Lever
(O/D Main Switch)
Input Speed Sensor (NT)NT
Output Speed Sensor (SP2)SP2
TH02
ATF (Automatic Transmission
Fluid) Temperature Sensor No. 2Skid Control ECUNSW
Park/Neutral Position Switch
R, D, 3, 2
VG
NE
L
ODMSIntegration Control and Panel
(Shift Position L Switch)
L4
: 4WD4WD Control ECU
CAN DI±520
± DIAGNOSTICSAUTOMATIC TRANSMISSION
714 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DIAGRAM
The configuration of the electronic control system in the A750E/A750F automatic transmission is as shown
in the following chart.
DIDIQ±01
± DIAGNOSTICSAUTOMATIC TRANSMISSION
DI±535
729 Author: Date:
2005 SEQUOIA (RM1146U)
ROAD TEST
1. PROBLEM SYMPTOM CONFIRMATION
Based on the result of the customer problem analysis, try to reproduce the symptoms. If the problem is that
the transaxle does not shift up, shift down, or the shift point is too high or too low, conduct the following road
test referring to the automatic shift schedule and simulate the problem symptoms.
2. ROAD TEST
NOTICE:
Perform the test at the normal operating ATF (Automatic Transmission Fluid) temperature: 50 to 80°C
(122 to 176°F).
(a) D position test:
Shift into the D position and fully depress the accelerator pedal and check the following points. Check
up±shift operation.
(1) Check up±shift operation.
Check that 1 " 2, 2 " 3, 3 " 4 and 4 " 5th up±shifts take place, and that the shift points conform
to the automatic shift schedule (See page SS±24).
HINT:
5th Gear Up±shift Prohibition Control
Engine coolant temperature is 55 °C (131 °F) or less and vehicle speed is at 51 km/h (32 mph) or less.
4th Gear Up±shift Prohibition Control
Engine coolant temperature is 40 °C (104 °F) or less and vehicle speed is at 45 km/h (28 mph) or less.
5th Gear Lock±up Prohibition Control
Brake pedal is depressed.
Accelerator pedal is released.
Engine coolant temperature is 60 °C (140 °F) or less.
(2) Check for shift shock and slip.
Check for shock and slip at the 1 " 2, 2 " 3, 3 " 4 and 4 " 5th up±shifts.
(3) Check for abnormal noise and vibration.
Check for abnormal noise and vibration when up±shifting from 1 " 2, 2 " 3, 3 " 4 and 4 " 5
while driving with the shift lever in the D position, and check while driving in the lock±up condition.
HINT:
The check for the cause of abnormal noise and vibration must be done thoroughly as it could also be due
to loss of balance in the differential, torque converter clutch, etc.
(4) Check kick±down operation.
Check vehicle speeds when the 2nd to 1st, 3rd to 2nd, 4th to 3rd, and 5th to 4th kick±downs take
place while driving with the shift lever in the D position. Confirm that each speed is within the
applicable vehicle speed range indicated in the automatic shift schedule (See page SS±24).
(5) Check abnormal shock and slip at kick±down.
(6) Check the lock±up mechanism.
Drive in the D position (5th gear), at a steady speed (lock±up ON).
Lightly depress the accelerator pedal and check that the engine speed does not change
abruptly.
HINT:
If there is a big jump in engine speed, there is no lock±up.
DI±536
± DIAGNOSTICSAUTOMATIC TRANSMISSION
730 Author: Date:
2005 SEQUOIA (RM1146U)
(b) 4 (O/D OFF) position test:
Shift into the 4 (O/D OFF) position and fully depress the accelerator pedal and check the following
points.
(1) Check up±shift operation.
Check that the 1 " 2, 2 " 3 and 3 " 4 up±shifts take place and that the shift point conforms
to the automatic shift schedule (See page SS±24).
HINT:
There is no 5th up±shift in the 4 position.
4th Gear Lock±up Prohibition Control
Brake pedal is depressed.
Accelerator pedal is released.
Engine coolant temperature is 60 °C (140 °F) or less.
(2) Check engine braking.
While driving in the 4 position and 4th gear, release the accelerator pedal and check the engine
braking effect.
(3) Check for abnormal noises during acceleration and deceleration, and for shock at up±shift and
down±shift.
(4) Check the lock±up mechanism.
Drive in 4 position 4th gear, at a steady speed (lock±up ON).
Lightly depress the accelerator pedal and check that the engine speed does not change
abruptly.
HINT:
If there is a big jump in engine speed, there is no lock±up.
(c) 3 position test:
Shift into the 3 position and fully depress the accelerator pedal and check the following points.
(1) Check up±shift operation.
Check that the 1 " 2 and 2 " 3 up±shifts takes place and that the shift point conforms to the
automatic shift schedule (See page SS±24).
HINT:
There is no 4th up±shift and lock±up in the 3 position.
When the 2nd start switch is ON, there is no 1 "2 up±shift and 2 "1 down±shift.
(2) Check engine braking.
While running in the 3 position and 3rd gear, release the accelerator pedal and check the engine
braking effect.
(3) Check for abnormal noises during acceleration and deceleration, and for shock at up±shift and
down±shift.
(d) 2 position test:
Shift into the 2 position and fully depress the accelerator pedal and check the following points.
(1) Check up±shift operation.
Check that the 1 " 2 up±shift takes place and that the shift point conforms to the automatic shift
schedule (See page SS±24).
HINT:
There is no 3rd up±shift and lock±up in the 2 position.
When the 2nd start switch is ON, there is no 1 "2 up±shift and 2 "1 down±shift.
DIDIW±01
± DIAGNOSTICSAUTOMATIC TRANSMISSION
DI±551
745 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR DRIVE PATTERN
1. MONITOR DRIVE PATTERN FOR ECT TEST
(a) Perform this drive pattern as one method to simulate the detection conditions of the ECT malfunctions.
(The DTCs may not be detected due to the actual driving conditions. And some codes may not be de-
tected through this drive pattern.)
HINT:
Preparation for driving
Warm up the engine sufficiently. (Engine coolant temperature is 60 °C (140 °F) or higher).
Drive the vehicle when the atmospheric temperature is ±10 °C (14 °F) or higher. (Malfunction is not
detected when the atmospheric temperature is ±10 °C (14 °F) or less).
Notice in driving
Drive the vehicle through all gears.
Stop " 1st " 2nd " 3rd " 4th " 5th " 5th (lock±up ON).
Repeat the above driving pattern three times or more.
NOTICE:
The monitor status can be checked using the OBD II scan tool. When using the hand±held tes-
ter, monitor status can be found in the ºENHANCED OBD II / DATA LISTº or under ºCARB OBD
IIº.
In the event that the drive pattern must be interrupted (possibly due to traffic conditions or other
factors), the drive pattern can be resumed and, in most cases, the monitor can be completed.
Perform this drive pattern on a level road as much as possible and strictly observe the posted
speed limits and traffic laws while driving.