2001 TOYOTA SEQUOIA ECU

DI±4
± DIAGNOSTICSENGINE
198 Author: Date:
2005 SEQUOIA (RM1146U) Speed sensor, Vehicle speed sensor ºAº, Speed sensor for
skid control ECU
Vehicle speed sensor
ATF temperature sensor, Trans. fluid temp. sensor, ATF
temperature sensor ºAºTransmission fluid temperature sensor
Electronic controlled automatic transmission, ECTElectronically controlled automatic
Intermediate shaft speed sensor ºAºCounter gear speed sensor
Output speed sensorOutput shaft speed sensor
Input speed sensor, Input turbine speed sensor ºAº, Speed
sensor (NT), Turbine speed sensorInput turbine speed sensor
PNP switch, NSWPark/neutral position switch
Pressure control solenoidTransmission pressure control solenoid
Shift solenoidTransmission shift solenoid valve
Transmission control switch, Shift lock control unitShift lock control module
Engine immobiliser system, Immobiliser systemVehicle anti±theft system
Air switching valve (ASV)Secondary air injection control valve
AI systemSecondary air injection system
Air pumpSecondary air injection pump
Air switching valve No.2 (ASV No.2)Secondary air injection bypass valve Bank 1, 2
VSV for air injection controlSecondary air injection vacuum switching valve
Air injection driverSecondary air injection driver

DI±30
± DIAGNOSTICSENGINE
224 Author: Date:
2005 SEQUOIA (RM1146U)
(a) Preconditions
The monitor will not run unless:

MIL is OFF

Fuel level is approximately 1/2 to 3/4

Altitude is 7,800 feet (2,400 m) or less

Engine Coolant Temperature (ECT) is between 4.4°C and 35°C (40°F and 95°F)

Intake Air Temperature (IAT) is between 4.4°C and 35°C (40°F and 95°F)

Cold Soak Procedure has been completed

Before starting the engine, the difference between ECT and IAT must be less than 7°C (13°F)
HINT:
Examples:

Scenario 1
ECT = 24°C (75°F)
IAT = 16°C (60°F)
Difference between ECT and IAT is 8°C (15°F)
" The monitor will not run because difference between ECT and IAT is higher than 7°C (13°F)

Scenario 2
ECT = 21°C (70°F)
IAT = 20°C (68°F)
Difference between ECT and IAT is 1°C (2°F)
" The monitor will run because difference between ECT and IAT is less than 7°C (13°F)
The readiness test can be completed in cold ambient conditions (less than 40°F / 4.4°C) and/or at
high altitudes (more than 7,800 feet / 2,400 m) if the drive pattern is repeated a second time after cycl-
ing the ignition off.
(b) Drive Pattern
(1) Connect the OBD II scan tool to DLC3 to check monitor status and preconditions (refer to (a)).
(2) Release pressure in fuel tank by removing the fuel tank cap and then reinstall it.
(3) Start the engine and allow it to idle until ECT becomes 75°C (167°F) or higher.
(4) Run the engine at 3,000 rpm for approximately 10 seconds.
(5) Allow the engine to idle with the A/C ON (to create slight load) for 15 to 50 minutes.
NOTICE:
If the vehicle is not equipped with A/C, put a slight load on the engine by doing the following :

Securely set the parking brake.

Block the drive wheels with wheel chocks.

Allow the vehicle to idle in drive for 15 to 50 minutes.

A23544
40 mph (64 km/h)
Idling
IG SW OFF ECT:
75C (167F) or higher
Vehicle Speed
Warming up(5)(6)
10 minutes
or more(7)
10 seconds
or more4 seconds
or moreTime At Least 3 times
(8) (9)
(10) Accelerator Pedal
DepressedAccelerator Pedal
Released (Fuel±cut)
± DIAGNOSTICSENGINE
DI±31
225 Author: Date:
2005 SEQUOIA (RM1146U)
5. AIR±FUEL RATIO (A/F) AND OXYGEN SENSOR (HO2) MONITOR (ACTIVE AIR±FUEL RATIO
CONTROL TYPE)
(a) Preconditions
The monitor will not run unless:

2 minutes or more have elapsed since the engine was started.

The Engine Coolant Temperature (ECT) is 75C (167F) or higher.

Air±fuel ratio feedback control is performed.

Fuel±cut control is performed for 8 seconds or more.
(b) Drive Pattern
(1) Connect the hand±held tester to DLC3.
(2) Turn the ignition switch to ON.
(3) Clear DTCs (see page DI±43).
(4) Start the engine, and warm it up until the ECT reaches 75C (167F) or higher.
(5) Drive the vehicle at 40 mph (64 km/h) or more for at least 10 minutes.
(6) Change the transmission to 2nd gear.
(7) Accelerate the vehicle to 30 mph (48 km/h) or more by depressing the accelerator pedal for at
least 10 seconds.
(8) Soon after performing step (8) above, release the accelerator pedal for at least 4 seconds without
depressing the brake pedal, in order to execute fuel±cut control.
(9) Stop the vehicle and allow the engine to idle for 10 seconds or more.
(10) Allow the vehicle to decelerate until the vehicle speed declines to less than 6 mph (10 km/h).
(11) Repeat steps from (8) through (10) above at least 3 times in one driving cycle.
(c) Monitor Status
(1) Check the Readiness Monitor status displayed on the tester.
(2) If the status does not switch to COMPL (complete), make sure that the preconditions have been
met, and then perform steps from (5) through (11) in Drive Pattern above.

DID7X±01
FI0534
D13872
Hand±Held Tester
DLC3
DI±40
± DIAGNOSTICSENGINE
234 Author: Date:
2005 SEQUOIA (RM1146U)
DIAGNOSIS SYSTEM
1. Description

When troubleshooting On±Board Diagnostic (OBD ll) ve-
hicles, the vehicle must be connected to the hand±held
tester. Various data output from the vehicle's ECM can
then be read.

OBD ll regulations require that the vehicle's on±board
computer illuminates the Malfunction Indicator Light (MIL)
on the instrument panel when the computer detects a
malfunction in: 1) the emission control system/compo-
nents, or 2) the powertrain control components (which af-
fect vehicle emissions), or 3) the computer. In addition,
the applicable Diagnostic Trouble Codes (DTCs) pre-
scribed by SAE J2012 are recorded in the ECM memory
(See page DI±58).
If the malfunction does not reoccur in 3 consecutive trips, the
MIL goes off automatically but the DTCs remain recorded in the
ECM memory.
To check the DTC, connect the hand±held tester or OBD II scan
tool to the Data Link Connector 3 (DLC3) of the vehicle. The
hand±held tester or OBD II scan tool also enables you to erase
the DTC and check the freeze frame data and various forms of
engine data (See the instruction manual for the hand±held tes-
ter). The DTC includes SAE controlled codes and manufacturer
controlled codes. SAE controlled codes must be set according
to the SAE, while manufacturer controlled codes can be set by
a manufacturer with certain restrictions (See the DTC chart on
page DI±58).
2. NORMAL MODE AND CHECK MODE
The diagnosis system operates in ºnormal modeº during normal
vehicle use. In ºnormal modeº, 2 trip detection logic* is used to
ensure accurate detection of malfunctions. A ºcheck modeº is
also available to technicians as an option. In ºcheck modeº, 1
trip detection logic is used for simulating malfunction symptoms
and increasing the system's ability to detect malfunctions, in-
cluding intermittent malfunctions (See page DI±11).
3. 2±TRIP DETECTION LOGIC
When a malfunction is first detected, the malfunction is tempo-
rarily stored in the ECM memory. This is known as 1st trip detec-
tion. If the ignition switch is turned OFF and then ON again, and
the same malfunction is detected again, the MIL will illuminate.
This is known as 2nd trip detection.

DID7Y±01
D13872
Hand±Held Tester
DLC3CAN VIM
± DIAGNOSTICSENGINE
DI±43
237 Author: Date:
2005 SEQUOIA (RM1146U)
DTC CHECK / CLEAR
1. CHECK DTC
DTCs which are stored in the ECM can be displayed with the
hand±held tester or generic OBD II scan tool.
These scan tools can display pending DTCs and current DTCs.
Some DTCs are not stored if the ECM does not detect a mal-
function during consecutive driving. However, the detected
malfunction during once driving is stored as pending DTC.
(a) Connect the hand±held tester to the CAN VIM. Then con-
nect the CAN VIM to the Data Link Connector 3 (DLC3).
(b) Turn the ignition switch to ON.
(c) Enter the following menus: DIAGNOSIS / ENHANCED
OBD II / DTC INFO / CURRENT CODES (or PENDING
CODE).
(d) Confirm the DTCs and freeze frame data and then write
them down.
(e) See page DI±58 to confirm the details of the DTCs.
NOTICE:
When simulating a symptom with the hand±held tester to
check the DTCs, use the normal mode. For DTC chart sub-
ject to º2 trip detection logicº, perform either of the follow-
ing actions.
Turn the ignition switch OFF after the symptom is simulated
once. Then repeat the simulation process again. When the
problem has been simulated twice, the MIL illuminates and the
DTCs are recorded in the ECM.
2. CLEAR DTC
(a) Connect the hand±held tester to the CAN VIM. Then con-
nect the CAN VIM to the DLC3.
(b) Turn the ignition switch to ON.
(c) Enter the following menus: DIAGNOSIS / ENHANCED
OBD II / DTC INFO / CLEAR CODES and press YES.

± DIAGNOSTICSENGINE
DI±49
243 Author: Date:
2005 SEQUOIA (RM1146U)PURGE DENSITY
Learning value of purge density/
Min.: ±50, Max.: 350Idling: ±40 to 0 %Service data
PURGE FLOWPurge flow:
Min.: 0 %, Max.: 102.4 %0 to 100 %: Idling'
EVAP PURGE VSVEVAP (Purge) VSV control duty:
Min.: 0 %, Max.: 100 %0 to 100 %: During idlingOrder signal from ECM
VAPOR PRESSVapor pressure:
Min.: ±4.125 kPa, Max.: 2.125 kPa0 kPa: Fuel tank cap removed
Pressure inside fuel tank moni-
tored by the vapor pressure sen-
sor
KNOCK CRRT VAL
Correction learning value of
knocking:
Min.: ±64 CA, Max.: 1,984 CA0 to 22 CA:
Driving, 44 mph (70 km/h)Service data
KNOCK FB VALFeedback value of knocking:
Min.: ±64 CA, Max.: 1,984 CA±22 to 0 CA
Driving, 44 mph (70 km/h)Service data
ACCEL POS #1
Absolute Accelerator Pedal Posi-
tion (APP) No. 1:
Min.: 0 %, Max.: 100 %10 to 22 %: accelerator pedal is
released
54 to 86 %: accelerator pedal is
fully depressed
'
ACCEL POS #2Absolute APP No. 2:
Min.: 0 %, Max.: 100 %
12 to 42 %: accelerator pedal is
released
66 to 98 %: The accelerator pedal
is fully depressed
'
ACCEL POS #1APP sensor No. 1 voltage:
Min.: 0 V, Max.: 4.98 V'ETCS freeze data
ACCEL POS #2APP sensor No. 2 voltage:
Min.: 0 V, Max.: 4.98 V'ETCS freeze data
ACCEL POS #1APP sensor No. 1 voltage:
Min.: 0 V, Max.: 5 V
0.5 to 1.1 V: accelerator pedal is
released.
2.6 to 4.5 V: or pedal is fully de-
pressed.
'
ACCEL POS #2APP sensor No. 2 voltage:
Min.: 0 V, Max.: 5 V
1.2 to 2.0 V: accelerator pedal is
released.
3.4 to 5.3 V: accelerator pedal is
fully depressed.
'
ACCEL IDL POS
Whether or not accelerator pedal
position sensor detecting idle:
ON or OFF
ON: Idling'
THRTL LEARN VAL
Throttle valve fully closed
(learned value):
0.4 to 0.8 V'
ACCEL SSR #1 AD
Accelerator fully closed value No.1
(AD):
Min.: 0, Max.: 4.98 V
'ETCS service data
ACCEL LRN VAL#1
Accelerator fully closed learning
value No.1:
Min.: 0, Max.: 124.512
'ETCS service data
ACCEL LRN VAL#2
Accelerator fully closed learning
value No.2:
Min.: 0, Max.: 124.512
'ETCS service data
FAIL #1
Whether or not fail safe function
executed:
ON or OFF
ON: ETCS has failed'
FAIL #2
Whether or not fail safe function
executed:
ON or OFF
ON: ETCS has failed'

B17411
E2 VC
E8ECM Connector
± DIAGNOSTICSENGINE
DI±135
329 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check voltage between terminals VC and E2 of ECM connector.
PREPARATION:
(a) Disconnect the T14 throttle control motor and sensor con-
nector.
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between the specified terminals of the E8
ECM connector.
OK:
Standard:
Tester ConnectionSpecified Condition
VC (E8±23) ± E2 (E8±28)4.5 to 5.5 V
NG Replace ECM (See page SF±80).
OK
4 Replace throttle body (See page SF±42).
Go
5 Check if DTC output recur.
PREPARATION:
(a) Clear the DTC (See page DI±43).
(b) Start the engine.
(c) Run the engine at idle for 15 seconds or more.
CHECK:
Read the DTC.
RESULT:
Display (DTC Output)Proceed to
ºP0120, P0122, P0123, P0220, P0222, P0223 and/or P2135º are output
againA
No DTC outputB
B System is OK.
A

± DIAGNOSTICSENGINE
DI±151
345 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
P0136
Heated rear oxygen sensor (Bank 1) output volt-
age (Output voltage)
P0136Heated rear oxygen sensor (Bank 1) impedance
(Low)
P0137
Heated rear oxygen sensor (Bank 1) output volt-
age (Low voltage)
P0137Heated rear oxygen sensor (Bank 1) impedance
(High)
P0138
Heated rear oxygen sensor (Bank 1) output volt-
age (High voltage)
RltdDTC
P0138Heated rear oxygen sensor (Bank 1) output volt-
age (Extremely high)
Related DTCs
P0156
Heated rear oxygen sensor (Bank 2) output volt-
age (Output voltage)
P0156Heated rear oxygen sensor (Bank 2) impedance
(Low)
P0157
Heated rear oxygen sensor (Bank 2) output volt-
age (Low voltage)
P0157Heated rear oxygen sensor (Bank 2) impedance
(High)
P0158
Heated rear oxygen sensor (Bank 2) output volt-
age (High voltage)
P0158Heated rear oxygen sensor (Bank 2) output volt-
age (Extremely high)
Rid / tMain sensors/componentsHeated rear oxygen sensorRequired sensors/componentsRelated sensors/componentsMass air flow meter
Frequency of operationOnce per driving cycle: Active air±fuel ratio control detection
Continuous: Others
Duration
20 sec.: Heated oxygen sensor output (Output voltage, High voltage, Low voltage)
30 sec.: Heated oxygen sensor impedance (Low)
90 sec.: Heated oxygen sensor impedance (High)
10 sec.: Heated oxygen sensor impedance (Extremely high)
MIL operation2 driving cycles Heated oxygen sensor output (Output voltage, High voltage, Low voltage)
Immediate: Heated oxygen sensor impedance (Low, High, Extremely high)
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
Heated oxygen sensor output voltage (Output voltage, High voltage and Low voltage):
Active air±fuel ratio controlExecuting
Active air±fuel ratio control being when all
of following conditions met±
Battery voltage11 V±
Engine coolant temperature75°C (167°F)±
IdleOFF
Engine RPM±3,200 rpm