2007 TOYOTA SIENNA ECU

TW–84TIRE AND WHEEL – TIRE PRESSURE WARNING VALVE AND TRANSMITTER
TW
REMOVAL
1. REMOVE FRONT WHEEL
2. REMOVE REAR WHEEL
3. REMOVE TIRE PRESSURE WARNING VALVE AND
TRANSMITTER
(a) Remove the valve core and cap, and release the air
from the tire.
(b) After ensuring that a sufficient amount of air has
been released, remove the nut and washer that are
used to secure the tire pressure warning valve and
transmitter. Drop the tire pressure warning valve
and transmitter inside the tire.
HINT:
Keep the removed cap, valve core, nut, and washer.
(c) After dropping the tire pressure warning valve and
transmitter into the tire, disengage the bead using
the shoe of the tire remover.
NOTICE:
Be careful not to damage the tire pressure
warning valve and transmitter due to
interference between the valve and the tire bead.
(d) Remove the bead on the upper side in the usual
way.
(e) Take out the tire pressure warning valve and
transmitter from the tire and remove the bead on the
lower side in the usual way.
NOTICE:
If replacing the tire pressure warning valve and
transmitter, make sure that a new grommet and
a new washer are used.
INSTALLATION
1. INSTALL TIRE PRESSURE WARNING VALVE AND
TRANSMITTER
(a) Insert the tire pressure warning valve and
transmitter into the valve installation hole. Insert it
from the inside of the rim so that the printed surface
can be seen.
NOTICE:
• Check that there is no visible deformation,
damage, or other abnormalities on the tire
pressure warning valve and transmitter.
• Check that there is no foreign matter on the
inner grommet and around the rim hole.
• If the tire pressure warning valve and
transmitter is installed upside down, it may
be damaged or fail to transmit signals when
running at high speeds.
• If installing a new tire pressure warning valve
and transmitter, write down the ID number
before installation.
• It is necessary to register the ID in the ECU
after installation (See page TW-20).
F046444E05
C156697E01

TW–28TIRE AND WHEEL – TIRE PRESSURE WARNING SYSTEM
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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
pushing 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 intelligent tester to DLC3.
(c) Turn the ignition switch to the ON position.
(d) Check that the tire pressure warning light comes on
for 3 seconds and then goes off.
(e) Select the TEST MODE on the intelligent tester.
(f) Confirm that the tire pressure warning light in the
combination meter blinks at 0.125-second intervals.
2. PERFORM SIGNAL CHECK
HINT:
• When entering signal check mode, the tire pressure
warning ECU sets all the signal check DTCs first.
After completing signal check for each inspection
item, the DTCs for systems that are determined to be
normal by the tire pressure warning ECU will be
erased.
The DTCs for other inspection items may not be
erased when only a certain signal is inspected.
• When signal check returns to normal mode, all the
signal check DTCs will be erased.
(a) Make sure that the ignition switch is off.
(b) Connect the intelligent tester to DLC3.
(c) Turn the ignition switch to the ON position.
C122887
F100632E04

TIRE AND WHEEL – TIRE PRESSURE WARNING SYSTEMTW–29
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(d) Select the SIGNAL CHECK on the intelligent tester.
HINT:
Every time the test mode DTC clear conditions are
satisfied, the tire pressure warning light comes on
for 1 second. Then, the tire pressure warning light
blinks at 0.125-second intervals.
(e) Drive the vehicle at 12 mph (20 km/h) or more for 10
seconds or more to check the vehicle speed signal
(C2191/91).
(f) Loosen the valve core and rapidly reduce the
pressure (at least 40 kPa (0.41 kg/cm
2, 5.8 psi)
within 30 seconds or more) to check the transmitter
data (C2181/81 to C2184/84).
HINT:
The transmitter ID can be transmitted by rapidly
reducing the tire pressure.
(g) Check that the tire pressure warning system test
mode DTCs are erased.
(h) Check the tire pressure warning reset switch.
(1) Press the tire pressure warning reset switch.
C110644
Test Mode DTC Test Signal Test Mode DTC Clear Condition
C2181/81 to C2184/84 Transmitter DataData is received from the transmitter which has a registered ID in
the tire pressure warning ECU
C2191/91 Vehicle Speed SignalVehicle speed of 12 mph (20 km/h) or more is detected for 3
seconds or more

TW–30TIRE AND WHEEL – TIRE PRESSURE WARNING SYSTEM
TW
(2) Check the tire pressure warning indicator light.
(i) Result
HINT:
After the signal check is completed, check for a
signal check DTC to confirm the system status.
(j) End of SIGNAL CHECK
After completing the test mode (SIGNAL CHECK),
turn the ignition switch off and disconnect the tester.
DTC of SIGNAL CHECK (TEST DIAGNOSIS)
function:
If a trouble code is displayed during the test mode
DTC check, check the circuit listed for that code. For
details of each code, refer to the relevant page listed
under respective "DTC No." in the chart.
Test Signal Normal Condition
Tire Pressure Warning Reset Switch• Switch ON: TPWS indicator comes on
• Switch OFF: TPWS indicator blinks at 0.125
Condition Procedure
SIGNAL CHECK DTC is output Repair the faulty part and enter SIGNAL CHECK again
SIGNAL CHECK DTCs are cleared No problem
DTC No. Detection Item Trouble Area See procedure
C2181/81 Transmitter ID1 not received• Tire pressure warning valve and transmitter
• Tire pressure warning antenna and receiver
• Wire harness or connector
• Tire pressure warning ECUTW-42
C2182/82 Transmitter ID2 not received• Tire pressure warning valve and transmitter
• Tire pressure warning antenna and receiver
• Wire harness or connector
• Tire pressure warning ECUTW-42
C2183/83 Transmitter ID3 not received• Tire pressure warning valve and transmitter
• Tire pressure warning antenna and receiver
• Wire harness or connector
• Tire pressure warning ECUTW-42
C2184/84 Transmitter ID4 not received• Tire pressure warning valve and transmitter
• Tire pressure warning antenna and receiver
• Wire harness or connector
• Tire pressure warning ECUTW-42
C2191/91 Vehicle speed signal error• Vehicle speed sensor
• Combination meter assembly
• Wire harness or connector
• Tire pressure warning ECUTW-70

TIRE AND WHEEL – TIRE PRESSURE WARNING ECUTW–87
TW
SUSPENSION & AXLE
TIRE AND WHEEL
TIRE PRESSURE WARNING ECU
COMPONENTS
C155500E01

TW–88TIRE AND WHEEL – TIRE PRESSURE WARNING ECU
TW
REMOVAL
NOTICE:
Before removing the tire pressure warning ECU, read the
registered transmitter IDs of all wheels and write them
down to use for re-registration of transmitter IDs (See
page TW-20).
1. DISCONNECT CABLE FROM NEGATIVE BATTERY
TERMINAL
CAUTION:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
2. REMOVE INSTRUMENT PANEL SAFETY PAD SUB-
ASSEMBLY
HINT:
Refer to the instructions for REMOVAL of the instrument
panel safety pad (See page IP-5).
3. REMOVE TIRE PRESSURE WARNING ECU
(a) Remove the screw.
(b) Disconnect the connector and remove the tire
pressure warning ECU.
INSTALLATION
1. INSTALL TIRE PRESSURE WARNING ECU
(a) Connect the connector to the tire pressure warning
ECU.
C156706
C156707
C156707

TIRE AND WHEEL – TIRE PRESSURE WARNING ECUTW–89
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(b) Install the tire pressure warning ECU with the screw.
2. INSTALL INSTRUMENT PANEL SAFETY PAD SUB-
ASSEMBLY
HINT:
Refer to the instructions for INSTALLATION of the
instrument panel safety pad (See page IP-14).
3. CONNECT CABLE TO BATTERY NEGATIVE
TERMINAL
4. REGISTER TRANSMITTER ID
HINT:
See page TW-20.
5. INSPECT TIRE PRESSURE WARNING SYSTEM
HINT:
See page TW-25.
6. INITIALIZE SYSTEM
NOTICE:
• Be sure to register the transmitter IDs of all tires
in the ECU before initialization.
• Be sure to inflate all tires to the proper inflation
pressure before initialization.
HINT:
See page TW-23.
C156706

TIRE AND WHEEL – TIRE PRESSURE WARNING SYSTEMTW–31
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PROBLEM SYMPTOMS TABLE
HINT:
• Use the table below to help determine the cause of the
problem symptom. The potential causes of the symptoms
are listed in order of probability in the "Suspected Area"
column of the table. Check each symptom by checking the
suspected areas in the order they are listed. Replace parts
as necessary.
• Inspect the fuses and relays related to this system before
inspecting the suspected areas below.
TIRE PRESSURE WARNING SYSTEM:
Symptom Suspected Area See page
Tire pressure warning light does not illuminate, despite
tire pressure decreasingInitializationTW-23
Check DATA LIST (Tire inflation pressure)TW-35
ID code check (Registration)TW-20
Tire pressure warning light illuminated (Goes off during
initial check)ECU power source circuitTW-77
Tire pressure warning light circuitTW-74
Tire pressure warning light illuminated (Comes on
during initial check)Check DATA LIST (Tire inflation pressure)TW-35
Tire pressure warning light circuitTW-74
ID code check (Registration)TW-20
Initialization cannot be done Tire pressure reset switch circuitTW-72
DTC check cannot be doneECU power source circuitTW-77
TC and CG terminal circuitTW-79