2001 TOYOTA SEQUOIA oil

DI±666
± DIAGNOSTICSAUTOMATIC TRANSMISSION
860 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P2740 Transmission Fluid Temperature Sensor ºBº
Circuit
DTC P2742 Transmission Fluid Temperature Sensor ºBº
Circuit Low Input
DTC P2743 Transmission Fluid Temperature Sensor ºBº
Circuit High Input
CIRCUIT DESCRIPTION
ATF (Automatic Transmission Fluid) temperature sensor No.2 is on the transmission and just in front of the
oil cooler inlet pipeline.
If ECM detects the abnormally high temperature of ATF by this sensor, it draws driver's attention by illuminat-
ing the warning lamp.
HINT:

The temperature of ATF easily rises when towing, climbing hills and in traffic, etc.

If the ATF temperature sensor No.2 becomes short±circuited, the signal that indicates the ATF temper-
ature is 150C (302F) or higher is input in ECM.
Vehicle conditions when the sensor is normal and when the sensor is short±circuited are indicated
in the table below.
ATF temperature Sensor No.2
StateDetection ConditionSymptomRecovery Condition

AT fluid temp. more than 150C
(302F).
AT Oil Temp. warning light re-
mains on
AT fluid temp. less than 135C
(275F). *2

AT fluid temp. more than 130C
(266F).
Shift point too high.
AT fluid temp. less than 110C
(230F).
Sensor is normalWhen the conditions (a) and (b)
are satisfied.
(a) AT fluid temp. more than 130C
(266F).
(b) Engine coolant temp. more
than 95C (203F).

Lock±up at 3rd gear. *1
AT fluid temp. less than 110C
(230F) *2 and engine coolant
temp. less than 95C (203F).
Sensor is short±circuited

Any conditions.

AT Oil Temp. warning light re-
mains on

Shift point too high.

Symptoms still occur
Sensor is short circuited

Engine coolant temp. more than
95C (203F).
Lock±up at 3rd gear. *1
Symptoms still occur
HINT:
*1: When AT fluid temperature is normal, transmission locks up at 5th gear with the shift lever in D position
and at 4th gear with the shift lever in 4 position.
*2: When AT fluid temperature is in normal range, it decreases to less than 135C (275F) within 5 minutes
with the shift lever in P or N position in an idling state.
DIDJN±01

DIDCN±01
F19465
: CAN
Compressor Assy
Combination Meter
Suspension
Control
ECU Exhaust Solenoid
Valve
Gate Solenoid Valve
Leveling Solenoid ValveAIR SUS Relay
Height Control Cylinder
(Pneumatic Cylinder)
Height Control Sensor
Sub±assy : ECU Output Signal
: ECU Input Signal
: Air Flow Path
Dryer
Height Control Cylinder
(Pneumatic Cylinder)
Speed Sensors

Engine Speed

L4 Switch

Shift Position
Information

Transmission
Model Informa-
tion

Height Control Mode Select
Switch

Height Control Switch

Courtesy Light Switches

Stop Light SwitchHI
N
LO
MAN. DI±700
± DIAGNOSTICSAIR SUSPENSION SYSTEM
894 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DESCRIPTION
1. GENERAL
This system uses pneumatic cylinders instead of the coil springs that are used in a conventional rear
suspension. The suspension control ECU analyzes the information based on the switches, sensors,
and input signals, operates the compressor assy, and uses the solenoid valves to control the vehicle
height.
The suspension control ECU detects, via the height control sensor, the changes in the rear vehicle
height that results from the number of occupants or the amount of the load. Then, the suspension con-
trol ECU controls the height control solenoid valves and the compressor assy in order to automatically
adjust the rear vehicle height to a constant (normal) vehicle height.
Furthermore, three vehicle heights can be selected by operating the height control switch: HI, NOR-
MAL, and LO. The HI vehicle height ensures the vehicle's drive±through performance on rough roads.
The LO vehicle height facilitates the entry and exit of the occupants and the loading and unloading
of cargo. The NORMAL vehicle height helps realize excellent controllability and riding comfort during
normal driving.

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±747
941 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1741/41 Air Sus Relay Circuit
CIRCUIT DESCRIPTION
When the ºUPº side of the height control switch is pressed, a signal is sent from terminal RC of the suspen-
sion control ECU to the AIR SUS relay to turn it on.
As a result, the current flows to the AIR SUS relay coil, closing the relay contact, and then the battery positive
voltage is applied to the compressor, which causes the compressed air to raise the vehicle height.
DTC No.DTC Detecting ConditionTrouble Area
C1741/41
Either of the following conditions is detected:
1. With the AIR SUS relay inactivated, an open signal of the
AIR SUS relay is detected for 1 sec. or more.
2. With the AIR SUS relay activated, a short signal of the AIR
SUS relay is detected 8 times successively.

AIR SUS relay

AIR SUS relay circuit

Suspension control ECU
HINT:
Once the ECU stores DTC C1741/41 in the memory, the vehicle height control is suspended until a normal
signal is input to the ECU from the AIR SUS relay. However, the control resumes if the ignition switch is turned
OFF, and then turned ON again.
DIDDT±01

DI93G±05
BR3583
BR3582F00010
RotorSpeed Sensor
Magnet
To ECU
+V
±VHigh Speed
Low Speed
CoilNS
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±925
111 9 Author: Date:
2005 SEQUOIA (RM1146U)
CIRCUIT INSPECTION
DTC
C0200 / 31 ± C0215 / 34Speed Sensor Circuit
CIRCUIT DESCRIPTION
The speed sensor detects wheel speed and sends the ap-
propriate signals to the ECU. These signals are used to control
the ABS control system. The front and rear rotors have 48
serrations each.
When the rotors rotate, the magnetic field emitted by the perma-
nent magnet in the speed sensor generates AC voltage. Since
the frequency of this AC voltage changes in direct proportion to
the speed of the rotor, the frequency is used by the ECU to de-
tect the speed of each wheel.

DTC No.DTC Detecting ConditionTrouble Area
C0200 / 31
C0205 / 32
C0210 / 33
C0215 / 34
When any of the following is detected:
1. During driving, speed sensor signals are not input for a
fixed time.
2. Momentary interruption in speed sensor signals occurs
many times during driving.
3. Abnormal signal occurs in pulse signal from speed sen-
sor during driving.
4. Speed sensor signal circuit continues to be open for a
fixed time.

Right front, left front, right rear and left rear speed sensor

Each speed sensor circuit

Sensor rotor

Skid control ECU
HINT:
DTC No. C0200 / 31 is for the right front speed sensor.
DTC No. C0205 / 32 is for the left front speed sensor.
DTC No. C0210 / 33 is for the right rear speed sensor.
DTC No. C0215 / 34 is for the left rear speed sensor.

F19773
ABS & VSC Actuator
(Skid Control ECU)
G±Y S14
Stop Light SW
I18 Ignition SW1 4 W
W±L
IG1
AM12
1
B±Y Instrument Panel J/B
2 1
1L
1F
1F1C
1C 1
2
46 STOP
AM1
ECU±IG W
4
B±R
Sub J/B No.3
3C8
3A8
B±R
B±R
J37AJ/C
J38AB8 Brake
Inhibit Relay
B±R L±OL±O
IL17
L±O
S1 38
BSW
STP S139
G±Y
IL2 13 12
3 4G±Y
4B1 1
14A
4C J11A
J10C J/C
CJ10G±Y G±W G±W
G±W
G±W B
J33
J34
H
G±W C
C
CJ44C
J45JR8 Rear Combination Light RH
1
4W±B
R7 Rear Combination Light LH
1
4 H9 High Mounted
Stop Light
A
A
A J19
J/C W±B
W±B
BD212
12W±B G±W
G±W
BD14
(*1) (*1)
(*2)(*2) W±B H9
High Mounted
Stop Light
1 2J57
J/C
BP BJ F10
Fusible
Link
Block ALT 8
5
B
Battery
*1: w/o Rear Spoiler
*2: w/ Rear Spoiler J/C
G±WJ/C
G±WSub J/B No.4
Stop Stop
DI±964
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1158 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM

F19773
ABS & VSC Actuator
(Skid Control ECU)
G±Y S14
Stop Light SW
I18 Ignition SW1 4 W
W±L
IG1
AM12
1
B±Y Instrument Panel J/B
2 1
1L
1F
1F1C
1C 1
2
46 STOP
AM1
ECU±IG W
4
B±R
Sub J/B No.3
3C8
3A8
B±R
B±R
J37AJ/C
J38AB8 Brake
Inhibit Relay
B±R L±OL±O
IL17
L±O
S1 38
BSW
STP S139
G±Y
IL2 13 12
3 4G±Y
4B1 1
14A
4C J11A
J10C J/C
CJ10G±Y G±W G±W
G±W
G±W B
J33
J34
H
G±W C
C
CJ44C
J45JR8 Rear Combination Light RH
1
4W±B
R7 Rear Combination Light LH
1
4 H9 High Mounted
Stop Light
A
A
A J19
J/C W±B
W±B
BD212
12W±B G±W
G±W
BD14
(*1) (*1)
(*2)(*2) W±B H9
High Mounted
Stop Light
1 2J57
J/C
BP BJ F10
Fusible
Link
Block ALT 8
5
B
Battery
*1: w/o Rear Spoiler
*2: w/ Rear Spoiler J/C
G±WJ/C
G±WSub J/B No.4
Stop Stop
DI±972
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1166 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM

DI1AP±40
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
DI±1573
1767 Author: Date:
2005 SEQUOIA (RM1146U)
PROBLEM SYMPTOMS TABLE
SymptomSuspected AreaSee page
Immobiliser is not set.
(Engine starts with key codes other than the registered key code.)1. Door courtesy light switch circuit (DTC12)
2. Transponder key ECUDI±1585
IN±35
Engine does not start.
1. Key
2. Key unlock warning switch circuit (DTC11)
3. Transponder key coil
4. Transponder key ECU
5. ECM*1
DI±1582
BE±143
IN±35
IN±35
Security indicator is always ON.
1. Security indicator
2. Security indicator light circuit
3. Transponder key ECU*2
DI±1597
IN±35
Security indicator is always ON.
(Although code has been registered in the automatic registration
mode, indicator is not OFF.)1. Transponder key coil
2. Transponder key ECUBE±143
IN±35
Security indicator is OFF.
(When DTC of immobiliser is output)1. Transponder key coil
2. Transponder key ECUBE±143
IN±35
Security indicator is OFF.
(When DTC of immobiliser is not output)1. Security indicator light circuit
2. Diagnosis circuit
3. Transponder key ECUDI±1597
DI±1599
IN±35
Security indicator is abnormally blinking.Transponder key ECUIN±35
No code is output.
1. Power source circuit
2. Diagnosis circuit
3. Transponder key ECUDI±1595
DI±1599
IN±35
*1 : Check that the key which did not start the engine has been registered, and that it is possible to start with
any other already registered key.
*2 : Finish the automatic registration mode because the mode might still be set.

DI1AM±35
DI±1578
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
1772 Author: Date:
2005 SEQUOIA (RM1146U)
DIAGNOSTIC TROUBLE CODE CHART
ECM DIAGNOSTIC TROUBLE CODE CHART (MIL)
DTC No.
(See page)Detection ItemTrouble Area
99
(DI±1580)Engine immobiliser system malfunction

Transponder key ECU

ECM

Wire harness
TRANSPONDER KEY ECU DIAGNOSTIC TROUBLE CODE CHART (SECURITY INDICATOR LIGHT)
DTC No.
(See page)Detection ItemTrouble Area
11
(DI±1582)Code 11 is not output

Unlock warning switch

Transponder key ECU

Wire harness
12
(DI±1585)Code 12 is not output

Driver door courtesy lamp switch

Transponder key ECU

Body ECU

Wire harness
13
(DI±1587)Code 13 is not output

Ignition switch

Transponder key ECU

Wire harness
21, 22
(DI±1589)Code 21 or 22 is not output

Key

Transponder key ECU

Transponder key amplifier with key coil

Wire harness
31, 35, 36, 37
(DI±1592)Code 31, 35, 36 or 37 is outputKey
32, 33
(DI±1593)Code 32 or 33 is output

Key

Transponder key ECU

Wire harness
34Code 34 is outputTransponder key ECU has no memory space to register anoth-
er key code
HINT:

DTCs 11, 12, 13, 21 and 22 are normal codes.

As for the normal codes, if the corresponding DTC is not output while operating any of the components
listed under ºTrouble Areaº, perform the inspection described in the reference pages.

DTCs 31, 32, 33, 34, 35, 36, 37 and 99 are abnormal codes.