TOYOTA SIENNA 2007 Service Repair Manual

BC–40BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEM
BC
(a) Check the battery voltage.
Standard voltage:
11 to 14 V
NG
OK
(a) Remove the ECU-IG fuse from the driver side J/B.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance
NG
OK
(a) Install the ECU-IG fuse.
(b) Connect the intelligent tester to the DLC3.
(c) Turn the ignition switch to the ON position and turn the
intelligent tester main switch on.
(d) Start the engine.
(e) Select the DATA LIST mode on the intelligent tester.
ABS:
(f) Measure the voltage output from the ECU displayed on
the intelligent tester.
OK:
"Normal" is displayed.
NG
OK
1INSPECT BATTERY
INSPECT CHARGING SYSTEM
2INSPECT FUSE (ECU-IG FUSE)
F045093E04
Tester Connection Specified Condition
ECU-IG (10 A) fuse Below 1
(Continuity)
REPLACE FUSE (ECU-IG FUSE)
3READ VALUE OF INTELLIGENT TESTER (IG1 POWER SUPPLY)
Item (Display)Measurement Item / Range
(Display)Normal Condition Diagnostic Note
IG VOLTAGEECU IG power supply voltage /
TOO LOW/NORMALTOO LOW: 9.5 V or less
NORMAL: 9.5 to 14.0 V-
REPAIR OR REPLACE HARNESS OR
CONNECTOR (IG1 CIRCUIT)

BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEMBC–41
BC
(a) Disconnect the skid control ECU connector.
(b) Turn the ignition switch to ON position.
(c) Measure the voltage according to the value(s) in the
table below.
Standard voltage
NG
OK
(a) Turn the ignition switch off.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance
NG
OK
(a) Clear the DTCs (See page BC-10).
(b) Check that the same DTC is recorded (See page BC-
10).
HINT:
Reinstall the sensors, connectors, etc. and restore the
vehicle to its prior condition before rechecking for DTCs.
Result
B
C
4INSPECT SKID CONTROL ECU (IG1 TERMINAL VOLTAGE)
C058919E24
Tester Connection Specified Condition
S3-3 (IG1) - Body ground 10 to 14 V
REPAIR OR REPLACE HARNESS OR
CONNECTOR (IG1 CIRCUIT)
5INSPECT SKID CONTROL ECU (GND TERMINAL CONTINUITY)
C058919E22
Tester Connection Specified Condition
S3-1 (GND1) - Body ground Below 1
S3-23 (GND2) - Body ground Below 1
REPAIR OR REPLACE HARNESS OR
CONNECTOR (GND CIRCUIT)
6RECONFIRM DTC
Condition Proceed to
DTC (C1241/41) is outputA
DTC (C1241/41) is not output (When troubleshooting in
accordance with the DTC CHART)B
DTC (C1241/41) is not output (When troubleshooting in
accordance with the PROBLEM SYMPTOMS TABLE)C
END
PROCEED TO NEXT CIRCUIT INSPECTION
SHOWN IN PROBLEM SYMPTOMS TABLE

BC–42BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEM
BC
A
REPLACE BRAKE ACTUATOR ASSEMBLY

BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEMBC–43
BC
DESCRIPTION
This skid control ECU inputs the stop light switch signal and detects the status of brake operation.
The skid control ECU has an open detection circuit. If an open in the stop light switch input line or GND
side stop light circuit is detected when the stop light switch is off, this DTC is output.
WIRING DIAGRAM
DTC C1249/49 Open in Stop Light Switch Circuit
DTC No. DTC Detection Condition Trouble Area
C1249/49With the IG1 terminal voltage at 10 V to 16 V, ABS is not
operating and stop light switch circuit is open for 1
second or more.• Stop light switch
• Stop light switch circuit
C160964E01

BC–44BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEM
BC
INSPECTION PROCEDURE
(a) Check that the stop light comes on when the brake pedal
is depressed, and goes off when the brake pedal is
released.
OK:
Stop light switch function is normal.
HINT:
Check the stop light bulb as it may have burnt out.
NG
OK
(a) Disconnect the skid control ECU connector.
(b) Measure the voltage according to the value(s) in the
table below.
Standard voltage
Result
B
C
A
(a) Clear the DTC (See page BC-10).
(b) Check that the same DTC is recorded (See page BC-
10).
HINT:
Reinstall the sensors, connectors, etc. and restore the
vehicle to its prior condition before rechecking for DTCs.
1CHECK STOP LIGHT SWITCH OPERATION
Go to step 4
2INSPECT SKID CONTROL ECU (STP TERMINAL VOLTAGE)
C058919E25
Tester Connection Condition Specified Condition
S3-16 (STP) - Body
groundStop light switch ON
(Brake pedal
depressed)8 to 16 V
S3-16 (STP) - Body
groundStop light switch OFF
(Brake pedal released)Below 1.5 V
Condition Proceed to
OK (When troubleshooting in accordance with the DTC CHART) A
OK (When troubleshooting in accordance with the PROBLEM
SYMPTOMS TABLE)B
NGC
PROCEED TO NEXT CIRCUIT INSPECTION
SHOWN IN PROBLEM SYMPTOMS TABLE
REPAIR OR REPLACE HARNESS OR
CONNECTOR (STP CIRCUIT)
3RECONFIRM DTC

BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEMBC–45
BC
Result
B
A
(a) Disconnect the stop light switch connector.
(b) Measure the voltage according to the value(s) in the
table below.
Standard voltage
NG
OK
(a) Measure the resistance according to the value(s) in the
table below.
Standard resistance
NG
OK
Condition Proceed to
DTC (C1249/49) is outputA
DTC (C1249/49) is not outputB
END
REPLACE BRAKE ACTUATOR ASSEMBLY
4INSPECT STOP LIGHT SWITCH (POWER SOURCE TERMINAL VOLTAGE)
I042363E11
Tester Connection Condition Specified Condition
S12-2 - Body ground Always 10 to 14 V
REPAIR OR REPLACE HARNESS OR
CONNECTOR (POWER SOURCE CIRCUIT)
5INSPECT STOP LIGHT SWITCH
C146625E04
Tester Connection Condition Specified Condition
1 - 2 Switch pin free Below 1
1 - 2 Switch pin pushed in 10 k or higher
REPLACE STOP LIGHT SWITCH

BC–46BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEM
BC
(a) Disconnect the skid control ECU connector.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance
HINT:
• When troubleshooting in accordance with the DTC
CHART, check DTCs before replacing the brake
actuator assembly (See page BC-10).
• When troubleshooting in accordance with the
PROBLEM SYMPTOMS TABLE, be sure to follow the
table before replacing the brake actuator assembly
(See page BC-7).
NG
OK
6CHECK HARNESS AND CONNECTOR (BETWEEN SKID CONTROL ECU AND STOP
LIGHT SWITCH)
C112579E03
Tester Connection Specified Condition
S3-16 (STP) - S12-1 Below 1
S3-16 (STP) - Body ground 10 k or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR
REPLACE BRAKE ACTUATOR ASSEMBLY

BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEMBC–47
BC
DESCRIPTION
The motor relay (semiconductor relay) is housed in the brake actuator assembly and drives the pump
motor based on a signal from the skid control ECU.
WIRING DIAGRAM
Refer to DTCs C0273/13 and C0274/14 (See page BC-31).
INSPECTION PROCEDURE
HINT:
After step 1 is complete, start the inspection from step 2 when using the intelligent tester, and from step 3
when not using the intelligent tester.
(a) Disconnect the skid control ECU connector.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance
NG
OK
(a) Reconnect the skid control ECU connector.
(b) Connect the intelligent tester to the DLC3.
(c) Turn the ignition switch to the ON position and turn the
intelligent tester main switch on.
(d) Start the engine.
(e) Select the ACTIVE TEST mode on the intelligent tester.
ABS:
(f) Check operating sound of the ABS motor when
operating it with the intelligent tester.
OK:
The operating sound of the ABS motor is heard.
NG
DTC C1251/51 Open in Pump Motor Circuit
DTC No. DTC Detection Condition Trouble Area
C1251/51ABS pump motor is not operating normally during initial
check.• ABS pump motor circuit
• Brake actuator assembly
1INSPECT SKID CONTROL ECU (GND TERMINAL CONTINUITY)
C058919E26
Tester Connection Specified Condition
S3-1 (GND1) - Body ground Below 1
S3-23 (GND2) - Body ground Below 1
REPAIR OR REPLACE HARNESS OR
CONNECTOR (GND CIRCUIT)
2PERFORM ACTIVE TEST BY INTELLIGENT TESTER (ABS MOTOR RELAY)
Item (Display) Vehicle Condition / Test Details Diagnostic Note
ABS MOT RELAY Turns ABS motor relay ON / OFF Operating sound of motor is heard
REPLACE BRAKE ACTUATOR ASSEMBLY

BC–48BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEM
BC
OK
(a) Clear the DTCs (See page BC-10).
(b) Start the engine.
(c) Drive the vehicle at the speed of 6 km/h (4 mph) or more.
(d) Check that the same DTC is recorded (See page BC-
10).
HINT:
• Reinstall the sensors, connectors, etc. and restore the
vehicle to its prior condition before rechecking for
DTCs.
• If a speed signal of 6 km/h (4 mph) or more is input to
the skid control ECU, with the ignition switch on and
the stop light switch off, the ECU performs self-
diagnosis of the motor and solenoid circuits.
Result
HINT:
• If any DTCs are output while jiggling a connector or
wire harness of the brake actuator (skid control ECU),
inspect and repair the connector or wire harness.
• If the normal system code is output, slightly jiggle the
connectors, wire harnesses, and fuses of the brake
actuator assembly. Make sure that no DTCs are
output.
• These DTCs may be stored due to a malfunction in
the connector terminal connection, etc.
B
A
3RECONFIRM DTC
Condition Proceed to
DTC (C1251/51) is outputA
DTC (C1251/51) not outputB
END
REPLACE BRAKE ACTUATOR ASSEMBLY

BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEMBC–49
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
C160965E01