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.
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
DI±807
1001 Author: Date:
2005 SEQUOIA (RM1146U)
4. CONFIRMATION OF TRANSMITTER ID REGISTRATION
(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) Select ºSIGNAL CHECKº mode on the hand±held tester (see page DI±810).
(e) Forcibly transmit the transmitter IDs for all wheels.
(1) When rapidly reducing the pressure, remove the valve core (above 20 kPa/15 sec.).
HINT:
The transmitter ID can be transmitted by rapidly reducing the tire air pressure.
When rapidly reducing the pressure, remove the valve core (above 20 kPa/15 secs.).
(2) Perform the steps mentioned above to all tires including the spare tire.
(f) Check that test mode DTCs C2181/81, C2182/82, C2183/83, C2184/84 and C2185/85 are all erased.
HINT:
The transmitter ID registration is complete when the test mode DTCs are erased.
If they haven't been erased, reset the tire pressure to the specified value and rotate the tire 90 to 270
degrees. Then forcibly transmit the transmitter IDs of all wheels. If they are still output, register the
transmitter IDs.
(g) Set the tire pressure of all wheels to the specified value.
DIDK0±01
F19150
Tire Pressure
Warning
Reset Switch
F19143
Tire Pressure Warning Lamp
ON
OFF1 sec.
1 sec. DI±808
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
1002 Author: Date:
2005 SEQUOIA (RM1146U)
INITIALIZATION
1. INITIALIZATION
NOTICE:
Initialization is necessary after replacing either the ECU,
tires with different tire pressure or tire pressure monitor
valve sub±assy, after rotating the tires, or when a new ve-
hicle is delivered.
(a) Set the tire air pressure for all wheels, including the spare,
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) Keep the tire pressure warning reset switch pressed for
3 seconds or more with the ignition switch on.
(c) Check that the tire pressure warning lamp blinks 3 times
(1 second ON, 1 second OFF).
HINT:
Do not turn the ignition switch off during initialization (The
initialization process takes about 20 minutes).
Initialization will be complete if signals are received from
all the wheels including the spare. Initialization will be
canceled if the ignition switch is turned off during initializa-
tion.
DIDKL±01
D05981DLC3
Hand±Held
Tester
F19915
DI±810
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
1004 Author: Date:
2005 SEQUOIA (RM1146U)
TEST MODE PROCEDURE
1. ENTER TEST MODE
HINT:
Operation of the tire pressure warning reset switch can be
checked in TEST MODE.
During TEST MODE, the system is not initialized by push-
ing the tire pressure warning reset switch. The circuit of
the tire pressure warning reset switch can be inspected
during this mode.
(a) Make sure that the ignition switch is off.
(b) Connect the hand±held tester to DLC3.
(c) Turn the ignition switch to the ON position.
(d) Select the TEST MODE on hand±held tester.
(e) Perform tire pressure warning reset switch test.
(1) Push the tire pressure warning reset switch.
(2) Check the tire pressure warning indicator lamp.
Test SignalNormal Condition
Tire Pressure Warning Reset SwitchSwitch ON: TPWS indicator come on
Switch OFF: TPWS indicator blinking
DIDK1±01
DI±814
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
1008 Author: Date:
2005 SEQUOIA (RM1146U)
PROBLEM SYMPTOMS TABLE
If a normal code is displayed during DTC check but the problem still occurs, check the circuits for each prob-
lem symptom in the order given in the table below and proceed to the relevant troubleshooting page.
SymptomSuspected AreaSee page
Tire pressure warning system does not operate.
1. Tire pressure monitor valve sub±assy
2. Tire pressure monitor receiver assy
3. Power source circuit
4. Tc terminal circuit
5. Combination meter assy
6. Tire pressure monitor ECU±
±
DI±878
DI±888
BE±55
±
DTC check cannot be done.
1. Power source circuit
2. Tc terminal circuit
3. Tire pressure monitor ECUDI±878
DI±888
±
Tire pressure warning lamp malfunctions (Does not light up).
1. Power source circuit
2. Tire pressure warning lamp circuit
3. Combination meter assy
4. Tire pressure monitor ECUDI±878
DI±873
BE±55
±
Tire pressure warning lamp malfunctions (Remains ON).
1. Tire pressure check
2. Tire pressure monitor ECU connector poorly connected
3. Tire pressure warning lamp circuit
4. Combination meter assy
5. Tire pressure monitor ECUSA±3
±
DI±873
BE±55
±
Tire pressure warning lamp malfunctions (Blinking).
1. Check DTC
2. Tc terminal circuit
3. Test mode (SIGNAL CHECK)
4. Tire pressure monitor ECUDI±820
DI±888
DI±810
±
Initialization cannot be done.
1. Test mode (SIGNAL CHECK)
2. Tire pressure warning reset switch
3. Tire pressure monitor ECUDI±810
DI±875
±