TOYOTA SIENNA 2007 Service Repair Manual

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
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(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
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SUSPENSION & AXLE
TIRE AND WHEEL
TIRE PRESSURE WARNING ECU
COMPONENTS
C155500E01

TW–88TIRE AND WHEEL – TIRE PRESSURE WARNING ECU
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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

TW–32TIRE AND WHEEL – TIRE PRESSURE WARNING SYSTEM
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TERMINALS OF ECU
1. CHECK TIRE PRESSURE WARNING ECU
HINT:
Inspect the connectors from the back side while the
connectors are connected.
(a) Disconnect the tire pressure warning antenna and
receiver connector.
(b) Measure the voltage according to the value(s) in the
table below.
(c) Connect the tire pressure warning antenna and
receiver connector.
(d) Measure the voltage and resistance according to
the value(s) in the table below. If the result is not as
specified, the ECU may have a malfunction.
E129452E15
Symbols (Terminal No.) Wiring Color Terminal Description ConditionSpecified Condition
T15-1 (CLSW) - T15-9 (GND) L-O - W-BTire pressure warning
reset switch• Ignition switch ON
• Tire pressure warning
reset switch on8.5 to 15 V
T15-1 (CLSW) - T15-9 (GND) L-O - W-BTire pressure warning
reset switch• Ignition switch ON
• Tire pressure warning
reset switch OFFBelow 1.5 V
T15-2 (SPD) - T15-9 (GND) V-W - W-B Vehicle speed signal Vehicle is running Pulse generation
T15-5 (IND) - T15-9 (GND) GR-L - W-BTire pressure warning light
output signal• Ignition switch ON
• Tire pressure warning
light offBelow 0.5 V
T15-5 (IND) - T15-9 (GND) GR-L - W-BTire pressure warning
reset switchAfter ignition switch is
turned ON, tire pressure
warning light illuminates
for 3 seconds.2.2 to 4.4 V
T15-6 (RF5V) - T15-9 (GND) P-L - W-BTire pressure warning
antenna and receiver
power sourceIgnition switch ON 11 to 14 V
T15-7 (IG) - T15-9 (GND) B-R - W-B IG power source Ignition switch ON 11 to 14 V
T15-10 (SIL) - T15-9 (GND) W - W-B Diagnostic communication Ignition switch ON 8 to 14 V
T15-11 (GND2) - T15-9 (GND) P - W-BTire pressure warning
antenna and receiver
groundAlways Below 1
T15-12 (RDA) - T15-9 (GND) G-B - W-BTire pressure warning
antenna and receiver
signalIgnition switch ON 11 to 14 V

TIRE AND WHEEL – TIRE PRESSURE WARNING SYSTEMTW–33
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(e) Using an oscilloscope, check the waveform 1.
(1) Waveform 1 (Reference)
(2) Waveform 2 (Reference)
F047507E08
Item Contents
Terminal SPD - GND
Tool setting 5 V/DIV, 200 ms./DIV.
Vehicle condition While driving at approximately 12 mph (20 km/h)
C107353E04
Item Contents
Terminal SIL - Body ground
Tool setting 5 V/DIV., 1 ms./DIV.
Vehicle condition Communicating using intelligent tester

TW–90TIRE AND WHEEL – TIRE PRESSURE WARNING RESET SWITCH
TW
SUSPENSION & AXLE
TIRE AND WHEEL
TIRE PRESSURE WARNING RESET SWITCH
COMPONENTS
C155499E01

TIRE AND WHEEL – TIRE PRESSURE WARNING RESET SWITCHTW–91
TW
REMOVAL
1. DISCONNECT CABLE FROM NEGATIVE BATTERY
TERMINAL
2. REMOVE FRONT DOOR SCUFF PLATE LH
3. REMOVE COWL SIDE TRIM SUB-ASSEMBLY LH
4. REMOVE LOWER INSTRUMENT PANEL FINISH
PANEL SUB-ASSEMBLY LH (See page IP-6)
5. REMOVE TIRE PRESSURE WARNING RESET
SWITCH
(a) Disengage the 2 claws and remove the tire pressure
warning reset switch from the lower instrument
panel finish panel sub-assembly LH.
INSPECTION
1. INSPECT TIRE PRESSURE WARNING RESET
SWITCH
(a) Remove the tire pressure warning reset switch.
(b) Measure the resistance between terminals 1 and 2
of the tire pressure warning reset switch when the
tire pressure warning switch is ON and OFF.
Standard resistance
If the result is not as specified, replace the tire
pressure warning reset switch.
C156708
C107260E01Switch Condition Specified Condition
ON Below 1
OFF 10 k or higher