2001 TOYOTA SEQUOIA ECU

F16805
Suspension Control ECU
Wire Harness View:
S25
IG
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±795
989 Author: Date:
2005 SEQUOIA (RM1146U)
2 Inspect suspension control ECU.
PREPARATION:
Disconnect the ECU connector.
CHECK:
Measure the voltage according to the value(s) in the table be-
low.
OK:
Tester connection
(Symbol)ConditionSpecified condition
S25±10 (IG) ±
Body groundIgnition switch OFF " ONBelow 1 V " 10 to 14 V
RESULT:
NGA
OK (When checking from step 1)B
OK (When checking from step 2)C
B Replace suspension control ECU
(See page IN±35).
C Proceed to next circuit inspection shown in
problem symptoms table (See page DI±716).
A
Repair or replace harness or connector.

DIDJT±01
F19148
Combination Meter
Tire Pressure
Warning Lamp DI±796
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
990 Author: Date:
2005 SEQUOIA (RM1146U)
TIRE PRESSURE WARNING SYSTEM
PRECAUTION
NOTICE:
When disconnecting the battery terminal, initialize the following system after the terminal is recon-
nected.
System NameSee Page
Back Door Power Window Control SystemBE±77
1. TIRE PRESSURE WARNING SYSTEM PRECAUTION
(a) When the tire pressure warning lamp comes on, immedi-
ately check the tire pressure of the tire and adjust it to the
specified pressure. (The tire pressure warning lamp
comes on if there is an open in the tire pressure warning
lamp circuit.)
NOTICE:
Check the spare tire as well since this system monitors
pressure of all tires, including the spare.
Tire sizeFrontRearSpare
P245 / 70 R 16220 kPa (2.2 kgf/cm2, 32 psi)240 kPa (2.4 kgf/cm2, 35 psi)240 kPa (2.4 kgf/cm2, 35 psi)
P265 / 70 R 16220 kPa (2.2 kgf/cm2, 32 psi)220 kPa (2.2 kgf/cm2, 32 psi)220 kPa (2.2 kgf/cm2, 32 psi)
P265 / 65 R 17220 kPa (2.2 kgf/cm2, 32 psi)220 kPa (2.2 kgf/cm2, 32 psi)220 kPa (2.2 kgf/cm2, 32 psi)
(b) When the tire pressure warning lamp blinks, there is a
malfunction in the system. Check for DTCs.
(c) It is necessary to register the transmitter ID in the tire pres-
sure monitor ECU when replacing the tire pressure moni-
tor valve sub±assy and/or tire pressure monitor ECU (see
page DI±805).
(d) When replacing the tire pressure monitor ECU.
(1) Using the DATA LIST, read the transmitter IDs regis-
tered in the ECU and make a note of them before
removing the tire pressure monitor ECU.
(2) Register the transmitter IDs after installing a new
tire pressure monitor ECU.
(e) When replacing the tire pressure monitor valve sub±assy.
(1) Make a note of the 7 digit number (transmitter ID)
written on the tire pressure monitor valve sub±assy
when replacing the tire pressure monitor valve sub±
assy. Register the transmitter IDs in the tire pres-
sure monitor ECU after replacing the tire pressure
monitor valve sub±assy and installing the tires and
wheels on the vehicle.

F19132
Transmitter ID
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
DI±797
991 Author: Date:
2005 SEQUOIA (RM1146U)
NOTICE:
The transmitter ID is written on the tire pressure monitor
valve sub±assy and ID can not be seen after installing the
tire pressure monitor valve sub±assy on the tire and wheel.
Therefore, make a note of the transmitter ID before instal-
ling the tire pressure monitor valve sub±assy.
2. IN CASE OF TIRE AND WHEEL REPLACEMENT
(a) When tires and wheels are replaced, register the transmitter ID without fail.
3. IN CASE OF TIRE ROTATION OR REPLACEMENT OF TIRE PRESSURE MONITOR ECU, TIRE
PRESSURE MONITOR VALVE SUB±ASSY, OR TIRES WITH DIFFERENT TIRE PRESSURE
(a) Initialize the tire pressure warning system after one of the following is performed:

Replacing the tire pressure monitor ECU or the tire pressure monitor valve sub±assy

Tire rotation

Replacing tires with different tire pressure
HINT:
The tire pressure warning system will not operate properly if it is not initialized (see page DI±808).
4. FAIL±SAFE FUNCTION
(a) When a system malfunction occurs in the tire pressure warning system, the tire pressure warning lamp
blinks and informs the driver of the system failure.
(b) The result of this diagnosis is stored in the tire pressure monitor ECU.

DIDJU±01
F19149
Tire Pressure Sensor
(Tire Pressure Monitor
Valve Sub±assy)
Tire Pressure Sensor
(Tire Pressure Monitor
Valve Sub±assy)Tire Pressure Sensor
(Tire Pressure Monitor
Valve Sub±assy) Combination Meter Assy

Tire Pressure Warning Lamp
Tire Pressure
Monitor ECU
Tire Pressure Warning
Reset Switch
Tire Pressure Sensor
(Tire Pressure Monitor Valve Sub±assy) Tire Pressure Sensor
(Tire Pressure Monitor
Valve Sub±assy)
Tire Pressure Monitor
Receiver Assy
DI±798
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
992 Author: Date:
2005 SEQUOIA (RM1146U)
LOCATION

DIDJV±01
F19126
Combination meter assy
(Vehicle speed signal)
Tire pressure monitor receiver assyCombination meter assy
(Tire pressure warning lamp) Tire
Pressure
Monitor
ECU
: Radio signal
Tire Pressure Sensor
(Tire pressure monitor valve
sub±assy) (FR LH)
Tire Pressure Sensor
(Tire pressure monitor valve
sub±assy) (FR RH)
Tire Pressure Sensor
(Tire pressure monitor valve
sub±assy) (RR LH)
Tire Pressure Sensor
(Tire pressure monitor valve
sub±assy) (RR RH)
Tire Pressure Sensor
(Tire pressure monitor valve
sub±assy) (SPARE)
DLC3
Tire pressure warning reset switch
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
DI±799
993 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DIAGRAM

DIDJW±01
F19887
Tire Pressure Monitor Valve Sub±assy
Tire Pressure
Warning Reset
Switch
Tire Pressure
Monitor ECU
Meter
DLC3
Tire Pressure Monitor Valve Sub±assyTire Pressure Monitor Receiver Assy
DI±800
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
994 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DESCRIPTION
1. DESCRIPTION OF SYSTEM
(a) A tire pressure monitor valve sub±assy equipped with a tire pressure sensor and a transmitter and is
installed in a tire wheel assy. The sensor measures the tire pressure and the measured value and
transmitter ID are transmitted to the tire pressure monitor receiver assy on the body as radio waves
and then sent to the tire pressure monitor ECU from the tire pressure monitor receiver. If the transmitter
ID has already been registered, the ECU compares the measured air pressure value with the standard
value. When the value is less than the standard value registered in the tire pressure monitor ECU, the
warning lamp on the combination meter comes on.

To address the differences in the air pressure settings by the type of tires, or the differences in
pressure between the front and rear tires, a tire pressure warning reset switch has been newly
adopted.

Along with the adoption of the tire pressure warning reset switch, the warning operation has been
changed.

TPWS transmitters with different bending angles as the tire pressure monitor valve sub±assy
have been provided for steel wheels with center ornaments. (They are not interchangeable with
aluminum wheels or steel wheels with full wheel caps.)
2. WHEN TIRE PRESSURE WARNING LAMP IS LIT
(a) When the warning lamp does not go off, or when it comes on during driving, check tire pressure. If the
warning lamp is lit even though the tire pressure is correctly adjusted, the tire could be punctured.
(b) Under the following conditions, the system may not function properly.

The areas, facilities or devices that use similar radio frequencies are located in the vicinity of the
vehicle.

A radio device of similar frequency is used in the vehicle.

A lot of snow or ice is stuck to the vehicle, especially onto the wheels and around the wheel
houses.

The battery of the sensor has been depleted.

The tires without tire pressure monitor valve sub±assy are used.

Tire chains are used.

± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
DI±801
995 Author: Date:
2005 SEQUOIA (RM1146U)

When the spare tire is not within the receivable range of the electric wave, a signal may not be
received because spare tires are fixed. Accordingly, the system may not function properly. If
there is a possibility that the TPWS system does not receive a signal from the spare tire, rotate
the tire 90°.
HINT:

If any other wheels than the specified ones are used, the system may not function properly because
the radio waves are differently transmitted from the tire pressure sensor.

Depending on the tire type, the system may not function properly even though the specified wheels
are used.
(c) The average use life of the grommet of the tire pressure monitor valve sub±assy is approximately 5
years, at which time it must be replaced.
(d) After removing and installing the ECU or a sensor, output a diagnosis code and check that it is a normal
code.
3. FUNCTION OF COMPONENTS
ComponentsFunction
Tire pressure monitor valve sub±assy
Combined as a single unit with a disc wheel air valve, it measures tire pressure and
temperature and transmits an ID number for measurement value and identification.
Built±in the battery.
Tire pressure monitor receiver assyReceives and transmits a necessary signal from the transmitter to the tire pressure
monitor ECU.
Tire pressure monitor ECU
Receives the signal from the receiver and identifies it as vehicle's own signal. If the
measurement value is equal to or lower than the specified value, it transmits a sig-
nal so that the air pressure warning lamp on the combination meter comes on.
Tire pressure warning lampLocated in the combination meter, it informs the driver of lowered tire air pressure
and system failure.
Tire pressure warning reset switchEnters the initialization mode for tire or wheel replacement, or tire rotation
4. TIRE PRESSURE WARNING RESET SWITCH

By operating the tire pressure warning reset switch, the tire pressure monitor ECU can be set to issue
a warning at an inflation pressure that corresponds to the type of tires. Therefore, the dealer must set
the warning threshold to the proper value in order to comply with the local regulations.

Operate the tire pressure warning reset switch only after the inflation pressures of all 5 tires (including
the spare) have been adjusted on the vehicle.

To initialize the system, press and hold the tire pressure warning reset switch for 3 seconds or longer
with the ignition switch ON. After the system has been initialized, the warning lamp blinks 3 times (1
second ON, 1 second OFF).

During initialization, the tire pressure monitor valve sub±assy measures the inflation pressure of the
tires, and registers the signals that are transmitted into the tire pressure monitor ECU at a frequency
of one per minute. The initialization process is completed when the signals from the 5 tires have been
received.

The initialization process is canceled if the ignition switch is turned OFF during initialization. To initialize
again, the tire pressure warning reset switch must be pressed again. For this reason, once the tire pres-
sure warning reset switch has been pressed, turning OFF the ignition switch is not recommended for
a minimum of 20 minutes.

DIDJZ±01
F19326
F19327
F19328
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
DI±805
999 Author: Date:
2005 SEQUOIA (RM1146U)
REGISTRATION
1. IN CASE OF TIRE PRESSURE MONITOR ECU REPLACEMENT
(a) Read ID stored in the old ECU using the hand±held tester.
2. IN CASE OF TIRE PRESSURE MONITOR VALVE SUB±ASSY AND/OR TIRE PRESSURE MON-
ITOR ECU REPLACEMENT
(a) Read ID written on the tire pressure monitor valve.
3. REGISTER TRANSMITTER ID
NOTICE:
It is necessary to register the transmitter ID in the tire pressure monitor ECU when replacing the tire
pressure monitor valve sub±assy and/or tire pressure monitor ECU.
(a) Set the tire pressure of all wheels to the specified value.
Tire sizeFrontRearSpare
P245 / 70 R 16220 kPa (2.2 kgf/cm2, 32 psi)240 kPa (2.4 kgf/cm2, 35 psi)240 kPa (2.4 kgf/cm2, 35 psi)
P265 / 70 R 16220 kPa (2.2 kgf/cm2, 32 psi)220 kPa (2.2 kgf/cm2, 32 psi)220 kPa (2.2 kgf/cm2, 32 psi)
P265 / 65 R 17220 kPa (2.2 kgf/cm2, 32 psi)220 kPa (2.2 kgf/cm2, 32 psi)220 kPa (2.2 kgf/cm2, 32 psi)
(b) Connect the hand±held tester to DLC3.
(c) Turn the ignition switch to the ON position.
(d) Read and write down the ID (ID1 to ID5) by using the
DATA LIST.
(e) Select the REGIST TIRE following the hand±held tester
screen.
(UTILITY ± REGIST TIRE)
(f) Input the ID (ID1 to ID5) using the hand±held tester and
transmit it to the tire pressure monitor ECU.
(g) Set the ID transmission condition to ºSUCCEEDEDº.
HINT:
If the operations of steps (d) to (f) do not complete within 5 min.,
the mode will return to normal operation mode.