Page 2408 of 3000

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
Page 2409 of 3000

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
Page 2410 of 3000
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
Page 2411 of 3000

BC–50BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEM
BC
INSPECTION PROCEDURE
(a) Check the skid control 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) Disconnect the skid control ECU connector.
(b) Turn the ignition switch to the 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
1INSPECT SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED
CONNECT CONNECTOR TO ECU
CORRECTLY
2INSPECT BATTERY
INSPECT CHARGING SYSTEM
3INSPECT 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)
4INSPECT 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)
Page 2412 of 3000
BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEMBC–51
BC
OK
(a) Disconnect the combination meter connector.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance
NG
OK
(a) Check the combination meter (See page ME-4).
HINT:
If troubleshooting has been carried out according to the
PROBLEM SYMPTOMS TABLE, refer back to the table
and proceed to the next step before replacing the part
(See page BC-7).
NG
OK
5CHECK HARNESS AND CONNECTOR (BETWEEN SKID CONTROL ECU AND
COMBINATION METER ASSEMBLY)
C 1111 6 2 E 0 4
Tester Connection Specified Condition
S3-30 (WA) - C10-7 Below 1
S3-30 (WA) - Body ground 10 k or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR
6INSPECT COMBINATION METER ASSEMBLY
REPLACE COMBINATION METER
ASSEMBLY
REPLACE BRAKE ACTUATOR ASSEMBLY
Page 2414 of 3000
BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEMBC–53
BC
(a) Turn the ignition switch off.
(b) Disconnect the combination meter connector.
(c) Measure the resistance according to the value(s) in the
table below.
Standard resistance
NG
OK
(a) Check the combination meter (See page ME-4).
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-7).
NG
OK
2CHECK HARNESS AND CONNECTOR (BETWEEN SKID CONTROL ECU AND
COMBINATION METER ASSEMBLY)
C 1111 6 2 E 0 4
Tester Connection Specified Condition
S3-30 (WA) - C10-7 Below 1
S3-30 (WA) - Body ground 10 k or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR
3INSPECT COMBINATION METER ASSEMBLY
REPLACE COMBINATION METER
ASSEMBLY
END
Page 2417 of 3000

BC–56BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEM
BC
(c) Measure the voltage according to the value(s) in the
table below.
Standard voltage
NG
OK
(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) Disconnect the parking brake switch connector.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance
NG
OK
C122930E14
Tester Connection Condition Specified Condition
S3-3 (IG1) - Body
groundIgnition switch ON (IG) 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)
6INSPECT PARKING BRAKE SWITCH
C106667E07
Tester Connection Condition Specified Condition
P6-1 - Body groundParking brake switch
ON
(Switch pin free)Below 1
P6-1 - Body groundParking brake switch
OFF
(Switch pin pushed in)10 k or higher
REPLACE PARKING BRAKE SWITCH
Page 2418 of 3000
BRAKE CONTROL – ANTI-LOCK BRAKE SYSTEMBC–57
BC
(a) Disconnect the skid control ECU connector and parking
brake switch.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance
NG
OK
(a) Remove the reservoir tank cap and strainer.
(b) Disconnect the brake fluid level warning switch
connector.
7CHECK HARNESS AND CONNECTOR
C122972E04
Tester Connection Specified Condition
S3-12 (PKB) - P6-1 Below 1
S3-12 (PKB) - Body ground 10 k or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR (PKB CIRCUIT)
8INSPECT BRAKE FLUID LEVEL WARNING SWITCH