2007 TOYOTA SIENNA tire pressure reset

TW–16TIRE AND WHEEL – TIRE PRESSURE WARNING SYSTEM
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SYSTEM DESCRIPTION
1. DESCRIPTION OF SYSTEM
(a) A tire pressure warning valve and transmitter is
equipped with a tire pressure sensor and a
transmitter and is installed in a tire wheel assembly.
The sensor measures the tire pressure. The
measured value and transmitter ID are transmitted
to the tire pressure warning antenna and receiver on
the body as radio waves and then sent to the tire
pressure warning ECU from the tire pressure
warning antenna and receiver. If the transmitter ID
has already been registered, the ECU compares the
measured air pressure value with the specified
value. When the value is less than the specified
value registered in the tire pressure warning ECU,
the warning light on the combination meter comes
on.
• The tire pressure warning reset switch addresses
the differences in the standard pressure of the
tire.
2. INITIAL CHECK
(a) The tire pressure warning light turns on for 3
seconds after the ignition switch ON and then goes
off.
HINT:
If the warning light does not turn on for 3 seconds,
troubleshoot the tire pressure warning light circuit.
C159181E01
C124985E04
Trouble Area See procedure
Tire pressure warning light circuitTW-74

TIRE AND WHEEL – TIRE PRESSURE WARNING SYSTEMTW–17
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3. WHEN TIRE PRESSURE WARNING LIGHT IS LIT
(a) When the tire pressure warning light does not go off,
or when it comes on during driving, check tire
pressure. If the tire pressure warning light comes on
within several hours after adjusting the tire
pressure, the tire may have a slow air leak.
(b) Under the following conditions, the system may not
function properly.
• 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 large amount of snow or ice is stuck to the
vehicle, especially onto the wheels and around
the wheel houses.
• The ID of the tire pressure warning valve and
transmitter has not been registered with the
ECU.
• A film or window tint that may interfere with radio
waves is attached on the glass.
• The battery of the sensor has been depleted.
• The tires without tire pressure warning valve and
transmitter are used.
• Tire chains are used.
• The use of non-genuine wheels may result in the
system failure or air-leak.
• Depending on the tire type, the system may not
function properly even though the specified
wheels are used.
(c) After removing and installing the ECU or a sensor,
check for a diagnostic trouble code and verify that it
is a normal code.
4. FUNCTION OF COMPONENTS
5. TIRE PRESSURE WARNING RESET SWITCH
• By operating the tire pressure warning reset switch,
the tire pressure warning ECU can be set to issue a
warning at an inflation pressure that corresponds to
the standard pressure of tires.
Therefore, the dealer must set the warning threshold
to the proper value in order to comply with the local
regulations.
Components Function
Tire pressure warning valve and transmitterCombined 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 warning antenna and receiverReceives and transmits a necessary signal from the transmitter to the tire pressure
warning ECU.
Tire pressure warning ECUReceives a signal from the receiver and identifies it as vehicle's own signal. If the
measured value is equal to or lower than the specified value, it transmits a signal so
that the tire pressure warning light on the combination meter comes on.
Tire pressure warning lightLocated in the combination meter, it informs the driver of lowered tire air pressure
and system failure.
Tire pressure warning reset switch Enters the initialization mode for the change of the standard pressure

TW–18TIRE AND WHEEL – TIRE PRESSURE WARNING SYSTEM
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• Operate the tire pressure warning reset switch only
after the inflation pressures of all tires 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 initialization
process has started, the warning light blinks 3 times
(1 second on, 1 second off).
• During initialization, the tire pressure warning valve
and transmitter measures the inflation pressure of the
tires, and registers the signals that are transmitted
into the tire pressure warning ECU at a frequency of
once per 3 minutes. The initialization process is
completed when signals from all the tires have been
received. It takes several minutes.

TW–26TIRE AND WHEEL – TIRE PRESSURE WARNING SYSTEM
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2. INITIALIZATION PROCEDURE
(a) Make sure that the ignition switch is off.
(b) Connect the intelligent tester to the DLC3.
(c) Turn the ignition switch to the ON position.
(d) Select "TIREPRESS" by following the prompts
displayed on the intelligent tester.
(e) Press the tire pressure warning reset switch within
30 seconds after turning the ignition switch ON.
Keep the tire pressure warning reset switch pressed
for 3 seconds or more with the ignition switch ON.
(f) Check that the tire pressure warning light blinks 3
times (1 second ON, 1 second OFF).
HINT:
Initialization will be completed if signals are received
from all the wheels.
(g) Wait for 5 to 6 minutes with the ignition switch ON.
NOTICE:
• The initialization is normally completed
within 5 to 6 minutes.
• If the initialization has not been completed
successfully, DTC C2177/77 is set after the
vehicle is driven for 20 minutes or more.
• The initialization can be terminated by
connecting terminals TC and CG of the DLC3
connector.
3. CHECK THAT INITIALIZATION HAS BEEN
COMPLETED
(a) Confirm that the data of tire pressure of all tires are
displayed on the intelligent tester screen.
TIRE PRESSURE:
C159182E02
F100115E55
Tester Display Measurement Item/Range Normal Condition Diagnostic Note
TIREPRESS1ID1 tire inflation pressure (Absolute
pressure) /
min.: 100 kPa (1 kgf/cm
2, 14 psi)
max.: 449.35 kPa (4.5 kgf/cm2, 63 psi)Actual tire inflation pressureIf 100 kPa (1 kgf/cm
2, 14 psi) for
absolute pressure is displayed, the
data has not been received.*
TIREPRESS2ID2 tire inflation pressure (Absolute
pressure) /
min.: 100 kPa (1 kgf/cm
2, 14 psi)
max.: 449.35 kPa (4.5 kgf/cm2, 63 psi)Actual tire inflation pressureIf 100 kPa (1 kgf/cm
2, 14 psi) for
absolute pressure is displayed, the
data has not been received.*

TW–22TIRE AND WHEEL – TIRE PRESSURE WARNING SYSTEM
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NOTICE:
• The transmitter ID is written on the tire
pressure warning valve and
transmitter. It will be unable to be read
after installing the tire pressure
warning valve and transmitter on the
tire and wheel. Therefore, take a note
of the transmitter ID before installing
the tire pressure warning valve and
transmitter.
• The ID registration must be performed
for all tire pressure warning valve and
transmitters. Check the DATA LIST,
replace the exchanged ID with a new
ID, and make a new data list of all 4
tires for the vehicle.
2. REGISTER TRANSMITTER ID (Using Intelligent
Te s t e r )
(a) Connect the intelligent tester to DLC3 (Procedure
"A").
(b) Turn the ignition switch to the ON position
(Procedure "B").
(c) Select the REGIST TIRE following the intelligent
tester screen (UTILITY - REGIST TIRE) (Procedure
"C").
(d) Input the IDs (ID1 to ID4) using the intelligent tester
and transmit them to the tire pressure warning ECU
(Procedure "D").
(e) Set the ID transmission condition to "ID Registration
is complete" (Procedure "E").
HINT:
• The previously registered IDs will be deleted
from the memory when the registration is
completed.
• If the procedures "C" to "D" are not completed
within 5 min., the mode will return to the normal
operation mode.
• If the registration cannot be completed with error,
connect TC to GND of DLC3, then retry.
• When the system is in initialization mode after
the tire pressure warning reset switch has been
operated, the registration is disabled until the
initialization process is canceled or completed.
F100622
C107265

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
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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