2007 TOYOTA SIENNA ECU

BC–140BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEM
BC
DESCRIPTION
The skid control ECU acquires steering angle sensor zero point every time the ignition switch is turned to
the ON position and the vehicle is driven at 35 km/h (22 mph) or more for approximately 5 seconds. The
ECU also stores the previous zero point.
If front wheel alignment or steering wheel position is adjusted without disconnecting the negative battery
terminal, or if yaw rate and deceleration sensor zero point is not acquired after the adjustments have been
completed, the skid control ECU detects the difference between the previous zero point and newly
acquired zero point and outputs this DTC to indicate a poor adjustment.
Warning of the steering angle sensor zero point malfunction will be cancelled by turning the ignition switch
off.
INSPECTION PROCEDURE
NOTICE:
When replacing the brake actuator assembly, perform zero point calibration (See page BC-70).
(a) Perform zero point calibration of the yaw rate and
deceleration sensor (See page BC-70).
HINT:
• When the stored zero point of the yaw rate and
deceleration sensor is erased, steering angle sensor
zero point will also be erased.
• If the zero point and output value of the yaw rate and
deceleration sensor and the output value of the speed
sensors are not normal, steering angle sensor zero
point cannot be acquired normally even if the vehicle
is driven straight ahead at 35 km/h (22 mph) or more.
NEXT
(a) Drive the vehicle straight ahead at 35 km/h (22 mph) or
more for at least 5 seconds.
(b) Check that the centered position of the steering wheel is
correctly set while driving straight ahead.
HINT:
If front wheel alignment and steering position are
adjusted as a result of abnormal centered position of the
steering wheel, acquire yaw rate and deceleration
sensor zero point again after the adjustments are
completed.
DTC C1290/66 Steering Angle Sensor Zero Point Malfunction
DTC Code DTC Detection Condition Trouble Area
C1290/66The steering angle sensor zero point calibration position
vastly differs from the recorded value• Yaw rate and deceleration sensor zero point
calibration incomplete
• Poor adjustment of the centered position of the
steering wheel
• Poor adjustment of front wheel alignment
1PERFORM ZERO POINT CALIBRATION OF YAW RATE AND DECELERATION SENSOR
2CHECK STEERING ANGLE SENSOR ZERO POINT CALIBRATION

BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEMBC–143
BC
DESCRIPTION
If any of the following is detected, the ABS warning light remains on.
• The skid control ECU connectors are disconnected from the skid control ECU.
• There is a malfunction in the skid control ECU internal circuit.
• There is an open in the harness between the combination meter and the skid control ECU.
HINT:
In some cases, the intelligent tester cannot be used when the skid control ECU is abnormal.
WIRING DIAGRAM
ABS Warning Light Remains ON
C160965E03

BC–144BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEM
BC
INSPECTION PROCEDURE
(a) Is DTC output for ABS?
Result
B
A
(a) Check the ECU connector's connecting condition.
OK:
The connector should be securely connected.
NG
OK
(a) Check the battery voltage.
Standard voltage:
11 to 14 V
NG
OK
(a) WHEN USING INTELLIGENT TESTER:
(1) Connect the intelligent tester to the DLC3.
(2) Start the engine.
(3) Select the DATA LIST mode on the intelligent tester.
ABS / VSC:
(4) Read the voltage condition output from the ECU
displayed on the intelligent tester.
OK:
"Normal" is displayed.
(b) WHEN NOT USING INTELLIGENT TESTER:
1CHECK DTC
Result Proceed to
DTC is not outputA
DTC is outputB
REPAIR CIRCUITS INDICATED BY OUTPUT
DTCS
2CHECK IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED
CONNECT CONNECTOR TO ECU
CORRECTLY
3CHECK BATTERY
CHECK OR REPLACE CHARGING SYSTEM
OR BATTERY
4INSPECT SKID CONTROL ECU (IG1 TERMINAL)
Tester Display Measurement Item/Range Normal Condition
IG VOLTAGEECU power supply voltage / UNDER /
NORMALNORMAL: 9.5 V or over
UNDER: Below 9.5 V

BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEMBC–145
BC
(1) Disconnect the skid control ECU connector.
(2) Turn the ignition switch to the ON position.
(3) Measure the voltage according to the value(s) in the
table below.
Standard voltage
NG
OK
(a) WHEN USING INTELLIGENT TESTER:
(1) Connect the intelligent tester to the DLC3 and start
the engine.
(2) Select the item "ABS WARN LIGHT" in the ACTIVE
TEST and operate the ABS warning light on the
intelligent tester.
(3) Check that "ON" and "OFF" of the ABS warning light
can be shown on the combination meter by the
intelligent tester.
(b) WHEN NOT USING INTELLIGENT TESTER:
(1) Turn the ignition switch off and disconnect the
connector from the skid control ECU.
(2) Ground the terminal WA of the skid control ECU.
(3) Turn the ignition switch to the ON position.
(4) Check that the ABS warning light goes off.
OK
NG
(a) Disconnect the skid control ECU connector.
G024767E47
Tester Connection Specified Condition
S3-46 (IG1) - S3-32 (GND1) 10 to 14 V
S3-46 (IG1) - S3-1 (GND2) 10 to 14 V
Go to step 6
5CHECK ABS WARNING LIGHT
G024767E48
REPAIR OR REPLACE ABS WARNING LIGHT
CIRCUIT
REPLACE BRAKE ACTUATOR ASSEMBLY
6CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BODY GROUND)

BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEMBC–147
BC
WIRING DIAGRAM
Refer to ABS Warning Light Remains ON (See page BC-141).
INSPECTION PROCEDURE
(a) Disconnect the skid control ECU connector.
(b) Turn the ignition switch to the ON position.
(c) Check that the ABS warning light comes on.
OK:
ABS warning light comes on.
HINT:
If troubleshooting has been carried out according to the
PROBLEM SYMPTOMS TABLE, refer back to the table
and proceed to the next step (See page BC-79).
NG
OK
(a) Turn the ignition switch off.
(b) Disconnect the combination meter connector.
ABS Warning Light does not Come ON
1CHECK ABS WARNING LIGHT
Go to step 2
REPLACE BRAKE ACTUATOR ASSEMBLY
2CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - COMBINATION METER)

BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEMBC–149
BC
DESCRIPTION
The skid control ECU is connected to the combination meter via CAN and multiplex communications.
If the skid control ECU stores DTCs to shut down TRAC and VSC operation, the VSC warning light comes
on in the combination meter.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
When replacing the brake actuator assembly, perform zero point calibration (See page BC-70).
(a) Check if the CAN communication system DTC is output
(See page CA-17).
VSC Warning Light Remains ON
1CHECK CAN COMMUNICATION SYSTEM
C160968E03

BC–150BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEM
BC
Result
B
A
(a) Check if the multiplex communication system DTC is
output (See page MP-14).
Result
B
A
(a) Check if the skid control ECU connector is securely
connected.
OK:
The connector is securely connected.
NG
OK
(a) Check the battery voltage.
Standard voltage:
11 to 14 V
NG
OK
(a) Check the combination meter (See page ME-4).
OK:
The combination meter is normal.
Result Proceed to
CAN communication system DTC is not output A
CAN communication system DTC is output B
INSPECT CAN COMMUNICATION SYSTEM
2CHECK MULTIPLEX COMMUNICATION SYSTEM
Result Proceed to
Multiplex communication system DTC is not output A
Multiplex communication system DTC is output B
INSPECT MULTIPLEX COMMUNICATION
SYSTEM
3CHECK IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED
CONNECT CONNECTOR TO ECU
CORRECTLY
4CHECK BATTERY
CHECK OR REPLACE CHARGING SYSTEM
OR BATTERY
5INSPECT COMBINATION METER ASSEMBLY

BC–152BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEM
BC
DESCRIPTION
The skid control ECU is connected to the combination meter via CAN and multiplex communications.
If the skid control ECU stores DTCs to shut down TRAC and VSC operation, the VSC warning light comes
on in the combination meter.
WIRING DIAGRAM
Refer to VSC Warning Light Remains ON (See page BC-147).
INSPECTION PROCEDURE
NOTICE:
When replacing the brake actuator assembly, perform zero point calibration (See page BC-70).
(a) Check if the CAN communication system DTC is output
(See page CA-17).
Result
B
A
(a) Check if the multiplex communication system DTC is
output (See page MP-14).
Result
B
A
(a) Connect the intelligent tester to the DLC3.
(b) Start the engine.
(c) Select the Active Test mode on the intelligent tester (See
page BC-85).
ABS / VSC:
VSC Warning Light does not Come ON
1CHECK CAN COMMUNICATION SYSTEM
Result Proceed to
CAN communication system DTC is not output A
CAN communication system DTC is output B
INSPECT CAN COMMUNICATION SYSTEM
2CHECK MULTIPLEX COMMUNICATION SYSTEM
Result Proceed to
Multiplex communication system DTC is not output A
Multiplex communication system DTC is output B
INSPECT MULTIPLEX COMMUNICATION
SYSTEM
3CHECK VSC WARNING LIGHT
Tester Display Test Part Control Range Diagnostic Note
VSC WARN LIGHT VSC warning light Warning light ON / OFF Observe combination meter