Page 1129 of 4323

± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±927
1121 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
Start the inspection from step 1 when using the hand±held tester and start from step 2 when not using the
hand±held tester.
1 Check output value of speed sensor.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch to the ON position and push the hand±held tester main switch ON.
(c) Select DATA LIST mode on the hand±held tester.
CHECK:
Check that there is no difference between the speed value output from the speed sensor displayed by the
hand±held tester and the speed value displayed by the speedometer when driving the vehicle.
ItemMeasurement Item /
Range (Display)Normal ConditionDiagnostic Note
WHEEL SPD FR
Wheel speed sensor (FR)
reading / min.: 0 MPH (0
km/h), max.: 202 MPH
(326 km/h)
Actual wheel speedSimilar speed as indicated
on speedometer
WHEEL SPD FL
Wheel speed sensor (FR)
reading / min.: 0 MPH (0
km/h), max.: 202 MPH
(326 km/h)
Actual wheel speedSimilar speed as indicated
on speedometer
WHEEL SPD RR
Wheel speed sensor (FR)
reading / min.: 0 MPH (0
km/h), max.: 202 MPH
(326 km/h)
Actual wheel speedSimilar speed as indicated
on speedometer
WHEEL SPD RL
Wheel speed sensor (FR)
reading / min.: 0 MPH (0
km/h), max.: 202 MPH
(326 km/h)
Actual wheel speedSimilar speed as indicated
on speedometer
OK:
There is almost no difference from the displayed speed value.
HINT:
There is tolerance of + 10 % in the speedometer indication.
OK Go to step 4.
NG
Page 1130 of 4323

R14205
21
R14205
21
DI±928
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1122 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check speed sensor.
Front:
PREPARATION:
(a) Make sure that there is no looseness at the connector
lock part and connecting part of the connector.
(b) Disconnect the speed sensor connector.
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector.
OK:
Resistance: 0.92 to 1.22 kW
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector and body ground.
OK:
Resistance: 1 MW or higher
Rear:
PREPARATION:
(a) Make sure that there is no looseness at the connector
lock part and connecting part of the connector.
(b) Disconnect the speed sensor connector.
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector.
OK:
Resistance: 1.8 to 2.2 kW
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector and body ground.
OK:
Resistance: 1 MW or higher
NG Replace speed sensor
(See page BR±56 or BR±59).
NOTICE:
Check the speed sensor signal after replacement (See
page DI±899).
OK
Page 1131 of 4323
BR3795OKNG
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±929
1123 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check for open and short circuit in harness and connector between each speed
sensor and skid control ECU (See page IN±35).
NG Repair or replace harness or connector.
OK
4 Check sensor installation.
CHECK:
Check the speed sensor installation.
OK:
The installation bolt is tightened properly and there is
no clearance between the sensor and the front steer-
ing knuckle or the rear axle carrier.
Torque: 8.0 N´m (82 kgf´cm, 71 in.´lbf)
NG Replace speed sensor
(See page BR±56 or BR±59).
NOTICE:
Check the speed sensor signal after replacement (See
page DI±899).
OK
Page 1132 of 4323

W04200
Normal Signal Waveform
1 V / Division2 m/s / DivisionGND
R07880
DI±930
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1124 Author: Date:
2005 SEQUOIA (RM1146U)
5 Check speed sensor and sensor rotor serrations.
INSPECTION USING OSCILLOSCOPE
PREPARATION:
Connect the oscilloscope to the terminal FR+ ± FR±, FL+ ± FL±,
RR+ ± RR± and RL+ ± RL± of the skid control ECU.
CHECK:
Drive the vehicle at about 12 mph (20 km/h), and check the sig-
nal waveform.
OK:
A waveform as shown in the figure should be output.
HINT:
As the vehicle speed (wheel revolution speed) increases,
a cycle of the waveform becomes shorter and the fluctua-
tion in the output voltage becomes greater.
When noise is identified in the waveform on the oscillo-
scope, error signals are generated due to the speed sen-
sor rotor's scratches, looseness or foreign matter depos-
ited on it.
OK Replace skid control ECU
(See page BR±52).
NOTICE:
When replacing the skid control ECU, perform the zero
point calibration (See page DI±897).
NG
6 Check sensor rotor and sensor tip.
Front:
PREPARATION:
Remove the disc (See page SA±22).
CHECK:
Check the sensor rotor serrations.
OK:
No scratches, missing teeth or foreign objects.
PREPARATION:
Remove the front speed sensor (See page BR±56).
CHECK:
Check the sensor tip.
OK:
No scratches or foreign objects on the sensor tip.
HINT:
Remove any foreign matter if identified.
Check the output waveform again after reassembly.
Page 1133 of 4323
W02871
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±931
1125 Author: Date:
2005 SEQUOIA (RM1146U)
Rear:
PREPARATION:
Remove the axle shaft (See page SA±95).
CHECK:
Check the sensor rotor serrations.
OK:
No scratches, missing teeth or foreign objects.
PREPARATION:
Remove the rear speed sensor (See page BR±59).
CHECK:
Check the sensor tip.
OK:
No scratches or foreign objects on the sensor tip.
NG Replace speed sensor or rotor.
NOTICE:
Check the speed sensor signal after replacement (See
page DI±899).
HINT:
Remove any foreign matter if identified.
Check the output waveform again after reassembly.
OK
Replace skid control ECU
(See page BR±52).
NOTICE:
When replacing the skid control ECU, perform the zero point calibration (See page DI±897).
Page 1134 of 4323
F19768
F10
Fusible Link Block
ABS
B
5
3B±R47
S1
W±B17
IL1W±B1
S1
W±BW±B A
A
J18
J/C
Battery
IG9
IL132
S1+BS
GND2ABS&VSC Actuator (Skid Control ECU)
IFL
IFR
IRL
IRR
OFL
OFR
ORL
ORR
ASR1
SV1
SV2
BATT ASR2 GND1Skid Control ECU DI±932
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1126 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C0226 / 21 ABS & VSC Solenoid Circuit
CIRCUIT DESCRIPTION
This solenoid turns on when signals are received from the ECU and controls the pressure acting on the wheel
cylinders to control braking force.
DTC No.DTC Detecting ConditionTrouble Area
C0226 / 21Solenoid valve signal does not match the check result.ABS & VSC actuator
ABS & VSC solenoid circuit
WIRING DIAGRAM
DI93H±03
Page 1135 of 4323
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±933
1127 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check DTC once more (See page DI±911).
PREPARATION:
(a) Clear the DTC.
(b) Turn the ignition switch OFF.
CHECK:
Turn the ignition switch to the ON position, and check if the same DTC still remains in the memory.
RESULT:
DTC is outputA
DTC is not outputB
B No problem.
A
Replace skid control ECU with actuator
(See page BR±51).
NOTICE:
When replacing the skid control ECU, perform the zero point calibration (See page DI±897).
Page 1136 of 4323
F19782
Battery16
S1+BS
GND1
GND2
+BM S1
S1 S1 47
1
32 B±R
B±R
W±B
W±B W±B W±B 5 BF10
Fusible Link BlockABS & VSC Actuator
(Skid Control ECU)
IG J18
J/C
A A3
ABS
Motor Relay
Pump
Motor IL117
IL19 DI±934
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1128 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C0278 / 11 ABS & VSC Relay Circuit
CIRCUIT DESCRIPTION
This relay supplies power to each ABS & VSC solenoid. If the initial check is OK, then the relay turns on after
the ignition switch is turned ON.
DTC No.DTC Detecting ConditionTrouble Area
C0278 / 11Relay circuit continues to be open for a fixed time when
solenoid relay is ON after ignition switch is turned ON.
ABS & VSC solenoid relay
ABS & VSC solenoid relay circuit
ABS & VSC motor relay
ABS & VSC motor relay circuit
WIRING DIAGRAM
DI93I±03