Right Front Wheel Speed Sensor Signal Malfunction - Vehicle Stability Control System (for BOSCH Made)

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM (for BOSCH Made): C0200/31,C0205/32,C1271/71,C1272/72,C1275/75,C1276/76,C1330/35,C1331/36: Right Front Wheel Speed Sensor Signal Malfunction
C1331/36 - Left Front Speed Sensor Circuit

DESCRIPTION

The speed sensors detects wheel speed and transmit the signals to the skid control ECU. These signals are used for control of the ABS control system. Each of the front and rear rotors has 48 serrations.

When the rotors rotate, the magnetic field generated by the permanent magnet in the speed sensor induces AC voltage. Since the frequency of this AC voltage changes in direct proportion to the speed of the rotor, the frequency is used by the ECU to detect the speed of each wheel.

DTCs C1271/71 to C1276/76 can be cleared when the speed sensor sends a wheel speed signal or the test mode ends. DTCs C1271/71 to C1276/76 are output only in the test mode.

HINT
DTC No. C0200/31 and C1330/35 are for the front speed sensor RH.

DTC No. C0205/32 and C1331/36 are for the front speed sensor LH.

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT
Check the condition of each related circuit connector before troubleshooting Electronic Circuit Inspection Procedure.

PROCEDURE

1. READ VALUE USING TECHSTREAM (FRONT SPEED SENSOR)

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Select "Data List" and read the value displayed on the Techstream Data List / Active Test.

ABS / VSC / TRAC

B -- INSPECT FRONT SPEED SENSOR INSTALLATION
A -- Continue to next step.

3. INSPECT SPEED SENSOR SIGNAL WAVEFORM

(a) Lift up the vehicle.

(b) Perform the inspection using an oscilloscope.

(1) Disconnect the front speed sensor connector.

(2) Connect the oscilloscope to terminals 1 and 2 of the front speed sensor.

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

OK:

The same waveform is output from front wheels and there is no noise or interference in the waveform.

HINT
* As vehicle speed (wheel rotation speed) increases, the width of the waveform narrows and the output voltage becomes greater.
* When noise is identified in the waveform on the oscilloscope, the erratic signals are generated due to rotor scratches, looseness or foreign matter attached to the speed sensor.

(4) Connect the connector.

NG -- INSPECT SPEED SENSOR TIP
OK -- Continue to next step.

4. RECONFIRM DTC

(a) Clear the DTCs Vehicle Stability Control System (for BOSCH Made).

(b) Drive the vehicle at a speed of approximately 25 mph (40 km/h) or more for 60 seconds or more.

(c) Check if the same DTCs are recorded Vehicle Stability Control System (for BOSCH Made).

HINT
Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

Result:

C -- END

B -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Problem Symptoms Table
A -- Continue to next step.

5. INSPECT FRONT SPEED SENSOR INSTALLATION

(a) Check the front speed sensor installation.

OK:

The installation bolt is tightened properly.

There is no clearance between the sensor and front steering knuckle.

Torque : 8.0 Nm (82 kgf-cm, 71 in-lbf)

NOTICE:
Check the speed sensor signal after replacement Test Mode Procedure.

NG -- INSTALL FRONT SPEED SENSOR CORRECTLY Installation
OK -- Continue to next step.

6. INSPECT FRONT SPEED SENSOR

(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.

(b) Disconnect the front speed sensor connectors.

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

Standard resistance:

LH
RH

NOTICE:
Check the speed sensor signal after replacement Test Mode Procedure.

NG -- REPLACE FRONT SPEED SENSOR Removal
OK -- Continue to next step.

7. CHECK HARNESS AND CONNECTOR (FRONT SPEED SENSOR TO SKID CONTROL ECU)

(a) Disconnect the skid control ECU connector.

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

Standard resistance:

LH
RH

(c) Connect the connectors.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (FRONT SPEED SENSOR TO SKID CONTROL ECU)
OK -- Continue to next step.

8. INSPECT SPEED SENSOR SIGNAL WAVEFORM

(a) Lift up the vehicle.

(b) Perform the inspection using an oscilloscope.

(1) Disconnect the front speed sensor connector.

(2) Connect the oscilloscope to terminals 1 and 2 of the front speed sensor.

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

OK:

The same waveform is output from all the 4 wheels and there is no noise or interference in the waveform.

HINT
* As vehicle speed (wheel rotation speed) increases, the width of the waveform narrows and the output voltage becomes greater.
* When noise is identified in the waveform on the oscilloscope, the erratic signals are generated due to rotor scratches, looseness or foreign matter attached to the speed sensor.

(4) Connect the connector.

NG -- INSPECT SPEED SENSOR TIP
OK -- Continue to next step.

9. READ VALUE USING TECHSTREAM (FRONT SPEED SENSOR)

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Select "Data List" and read the value displayed on the Techstream Data List / Active Test.

ABS / VSC / TRAC

(d) Check that there is no difference between the speed value output from the speed sensor displayed on the Techstream and the speed value displayed on the speedometer when driving the vehicle.

OK:

The speed value output from the speed sensor displayed on the Techstream is the same as the actual vehicle speed.

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 Problem Symptoms Table.

NG -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal
OK -- Continue to next step.

10. RECONFIRM DTC

(a) Clear the DTCs Vehicle Stability Control System (for BOSCH Made).

(b) Drive the vehicle at a speed of approximately 25 mph (40 km/h) or more for 60 seconds or more.

(c) Check if the same DTCs are recorded Vehicle Stability Control System (for BOSCH Made).

HINT
Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

Result:

C -- END

B -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Problem Symptoms Table
A -- Continue to next step.

11. INSPECT SPEED SENSOR TIP

(a) Remove the front speed sensor.

(b) Check the sensor tip.

OK:

No scratches or foreign matter on the sensor tip.

NOTICE:
Check the speed sensor signal after cleaning or replacement Test Mode Procedure.

(c) Install the speed sensor.

NG -- CLEAN OR REPLACE SPEED SENSOR

OK -- CLEAN OR REPLACE SPEED SENSOR ROTOR