Inspection Procedure

HINT:

When C1241/41 is output together with C0278/11, inspect and repair the trouble areas indicated by C1241/41.

INSPECT FUSE (ABS/VSC No.2 FUSE)

(a) Remove the ABS/VSC No.2 fuse from the engine room R/B.

(b) Measure the resistance according to the value(s) in the table below.

Resistance

Tester Connection

Specified Condition

ABS/VSC No.2 fuse

Below 1 Q (Continuity)

NGj>

INSPECT FOR SHORT IN ALL COMPONENTS CONNECTED TO FUSE AND REPAIR OR REPLACE THEM IF NEEDED, AND REPLACE FUSE

INSPECT SKID CONTROL ECU CONNECTOR (+BS TERMINAL VOLTAGE)

Skid Control ECU

(harness side connector front view)

(a) Disconnect the skid control ECU connector.

(b) Measure the voltage according to the value(s) in the table below.

Voltage

Tester Connection

Condition

Specified Condition

A40-3 (+BS) - Body ground

Always

10 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR (+BS CIRCUIT)

INSPECT SKID CONTROL ECU CONNECTOR (GND TERMINAL CONTINUITY)

Skid Control ECU

(harness side connector front view)

(a) Disconnect the skid control ECU connector.

(b) Measure the resistance according to the value(s) in the table below.

Resistance

Tester Connection

Specified Condition

A40-4 (GND1) - Body ground

REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT)

RECONFIRM DTC

Result

HINT:

This codes is detected when a problem is identified in the brake actuator assembly.

The solenoid circuit is in the brake actuator assembly. Therefore, solenoid circuit inspection and solenoid unit inspection cannot be performed. Be sure to check if the DTC code is output before replacing the brake actuator assembly.

(b) Start the engine.

(c) Drive the vehicle at the speed of 12 mph (20 km/h) or more for 30 seconds or more.

(d) Check that the same DTC is recorded.

Result

Result

Proceed to

DTC is not output

A

DTC is output

• If the normal system code is output (the malfunction code is not output), slightly jiggle the connectors, wire harnesses, and fuses of the brake actuator assembly. Make sure that no DTCs are output.

• 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.

• These DTCs may be stored due to a malfunction in the connector terminal connection, etc.

REPLACE BRAKE ACTUATOR ASSEMBLY

C1237/37

Speed Sensor Rotor Faulty

DESCRIPTION

This code is output when a difference in tire size, foreign matter attached to a speed sensor tip or a sensor rotor, or a missing rotor serration is detected.

This code may be output when a malfunction in the terminal of the speed sensor circuit connector or wire harness is detected.

DTC No.

DTC Detecting Condition

Trouble Area

C1237/37

When any of the following (1 to 3) is detected:

1. Wheel speed difference between the wheels.

2. Wheel sensor signal failure.

3. Continuous ABS control for 60 sec. or more.

• Brake actuator assembly (skid control ECU)

• Speed sensor rotor (Front)

• Rear axle hub & bearing assembly

• Speed sensor circuit

• Tire deformation

INSPECTION PROCEDURE

INSPECT TIRE

(a) Check the size and condition of all 4 tires. HINT:

This DTC is output when tire deformation or a difference in tire size is detected.

The diameter of all 4 tires and air pressure are the same.

REPLACE TIRES SO THAT ALL 4 TIRES ARE SAME IN SIZE

INSPECT SPEED SENSOR AND SENSOR ROTOR SERRATIONS

Skid Control ECU

(harness side connector front view)

(a) INSPECTION USING OSCILLOSCOPE

(1) Disconnect the skid control ECU connector.

(2) Connect the oscilloscope to each speed sensor terminal of the skid control ECU connector.

Connector

Circuit

A40-5 (FL+) - A40-6 (FL-)

Front left speed sensor

A40-10 (FR+) - A40-9 (FR-)

Front right speed sensor

A40-7 (RL+) - A40-17 (RL-)

Rear left speed sensor

A40-19 (RR+) - A40-8 (RR-)

Rear right speed sensor

Was Bedeutet Frequenz Einer Schallwelle

(3) Check that a waveform is output when the tires are rotated (by the sensor circuit).

A waveform as shown in the figure should be output.

HINT:

• Each sensor circuit outputs the same waveform without noise.

• As vehicle speed (wheel rotation speed) increases, the width of the waveform narrows and the fluctuation in the output voltage becomes greater.

• When noise is identified in the waveform on the oscilloscope, error signals are generated due to rotor scratches, looseness or foreign matter attached to the speed sensor.

(4) Make sure that the waveform does not change while jiggling a connector or a wire harness.

The waveform does not change.

HINT:

If the waveform changes while jiggling a connector or a wire harness, there may be a malfunction in the connector on the wire harness.

Result

Result

Proceed to

OK

A

NG (waveform changes while jiggling a connector or a wire harness)

B

NG (waveform does not change while jiggling a connector or a wire harness)

C

REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL ECU TO SPEED SENSOR)

CHECK OR REPLACE SPEED SENSOR AND SENSOR ROTOR

RECONFIRM DTC

(b) Start the engine.

(c) Drive the vehicle at the speed of 20 mph (32 km/h) or more for 60 seconds or more.

(d) Check that the same DTC is recorded.

Result

Result

Proceed to

DTC is not output

A

DTC is output

REPLACE BRAKE ACTUATOR ASSEMBLY

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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