warning light TOYOTA SIENNA 2007 Service Service Manual

TW–78TIRE AND WHEEL – TIRE PRESSURE WARNING SYSTEM
TW
(a) Disconnect the C10 combination meter connector.
(b) Disconnect the T15 tire pressure warning ECU
connector.
(c) Measure the resistance according to the value(s) in the
table below.
Standard resistance
NG
OK
(a) Disconnect the connector from the tire pressure warning
ECU.
(b) Turn the ignition switch to the ON position, and check if
the tire pressure warning light illuminates.
Result
B
1CHECK HARNESS AND CONNECTOR (COMBINATION METER - TIRE PRESSURE
WARNING ECU)
C159184E03
Tester Connection Condition Specified Condition
C10-6 (TIRE) - T15-5
(IND)
AlwaysBelow 1
C10-6 (TIRE) - Body
ground10 k or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR
2INSPECT COMBINATION METER
C148851E05
Result Proceed to
Illuminates A
Does not illuminate B
REPLACE COMBINATION METER (See page
ME-51)

TW–82TIRE AND WHEEL – TIRE PRESSURE WARNING SYSTEM
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DESCRIPTION
DTC output mode is set by connecting terminals 13 (TC) and 4 (CG) of the DLC3. The DTCs are indicated
by blinks of the tire pressure warning light.
WIRING DIAGRAM
HINT:
When each warning light blinks continuously, a ground short in the wiring of terminal TC of the DLC3 or an
internal ground short in an ECU connected to this circuit may have occurred.
INSPECTION PROCEDURE
NOTICE:
When replacing the tire pressure warning ECU, read the transmitter IDs stored in the old ECU
using the intelligent tester and write them down before removal.
It is necessary to register an ID code after replacing the tire pressure warning valve and
transmitter and/or the tire pressure warning ECU (See page TW-20).
TC and CG Terminal Circuit
E110507E38

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–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
TW
(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 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
TW
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–35
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3. DIAGNOSIS SYSTEM
(a) DTCs (Normal mode)
(1) DTCs are memorized in the tire pressure
warning ECU and read by the blinks of the tire
pressure warning light or by using the intelligent
tester (See page TW-34).
(b) Test mode
(1) By switching from normal mode into test mode
(input signal check), you can inspect the tire
pressure warning antenna and receiver, each
tire pressure warning valve and transmitter, and
vehicle speed sensor (See page TW-25).
(c) When there is a problem with the tire pressure
warning system, the tire pressure warning light
blinks at 0.5-second intervals, and turns on after 1
minute.
4. CHECK TIRE PRESSURE WARNING LIGHT
(a) Turn the ignition switch to the ON position.
(b) Check that the tire pressure warning light comes on
for 3 seconds.
If the warning check result is not normal, proceed to
the troubleshooting for the tire pressure warning
light circuit.
5. TIRE PRESSURE WARNING LIGHT AND INDICATOR
CHART
HINT:
The table below indicates the state of the tire pressure
warning light and indicator after the ignition switch ON.
C159176E01
Trouble Area See page
Tire pressure warning light circuitTW-74
Immediately
after turning
the ignition
switch ONAlways
Warning light output pattern
Comes on for
3 sec.Goes off Comes on Blinks (*1) Blinks (*2) Blinks (*3) Blinks (*4) Outputs DTC
Normal
--- - - -
Low tire
pressure
--- - - -
System fail
---- - -
Te s t m o d e
------
Initialization
- -----
ECU
connector
poorly
connected---
-- - -
TC ground
(DTC is
output)
- --- - -
TC ground
(DTC is not
output)- --- --

TIRE AND WHEEL – TIRE PRESSURE WARNING SYSTEMTW–37
TW
DTC CHECK / CLEAR
1. DTC CHECK (USING SST CHECK WIRE)
(a) Check DTCs.
(1) Turn the ignition switch off.
(2) Using SST, connect terminals TC and CG of
DLC3.
SST 09843-18040
(3) Turn the ignition switch to the ON position.
(4) Read and record any DTCs from the tire
pressure warning light on the combination meter.
Refer to the illustration as examples of a normal
system code and codes 13 and 33.
HINT:
• If the tire pressure warning light does not
indicate any DTCs or the normal system
code, inspect the tire pressure warning light
circuit or TC and CG terminal circuit.
• If 2 or more malfunctions are indicated at the
same time, the lowest numbered DTC is
displayed first.
(5) Refer to the Diagnostic Trouble Code Chart (See
page TW-37) for DTC information.
(6) After completing the check, turn the ignition
switch off and remove SST from DLC3.
SST 09843-18040
2. DTC CHECK (USING INTELLIGENT TESTER)
(a) Check DTCs.
(1) Make sure that the ignition switch is off.
(2) Connect the intelligent tester to the DLC3.
(3) Turn the ignition switch to the ON position.
(4) Read the DTCs following the prompts on the
tester screen.
HINT:
Refer to the intelligent tester operator's manual
for further details.
(b) Clear the DTCs.
HINT:
After repairing the malfunctions, clear the DTCs.
(1) Make sure that the ignition switch is off.
(2) Connect the intelligent tester to DLC3.
(3) Turn the ignition switch to the ON position.
(4) Clear the DTCs following the prompts on the
tester screen.
HINT:
Refer to the intelligent tester operator's manual
for further details.
C159183E02
Trouble Area See page
Tire pressure warning light circuitTW-74
TC and CG terminal circuitTW-79