Vehicle Stability Control System

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C0200/31: Front Speed Sensor RH Circuit

DTC C0200/31 - Front Speed Sensor RH Circuit

DTC C0205/32 - Front Speed Sensor LH Circuit

DTC C1235/35 - Foreign Object is Attached on Tip of Front Speed Sensor RH

DTC C1236/36 - Foreign Object is Attached on Tip of Front Speed Sensor LH

DTC C1271/71 - Low Output Signal of Front Speed Sensor RH (Test Mode DTC)

DTC C1272/72 - Low Output Signal of Front Speed Sensor LH (Test Mode DTC)

DTC C1275/75 - Abnormal Change in Output Signal of Front Speed Sensor RH (Test Mode DTC)

DTC C1276/76 - Abnormal Change in Output Signal of Front Speed Sensor LH (Test Mode DTC)

DESCRIPTION

The speed sensor detects wheel speed and transmits the appropriate signals to the skid control ECU. These signals are used for control of the ABS 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 skid control ECU to detect the speed of each wheel.
DTCs C1271/71, C1272/72, C1275/75 and C1276/76 are output only in test mode (SIGNAL CHECK).

HINT:
- DTC C0200/31 and C1235/35 are for the right front speed sensor.
- DTC C0205/32 and C1236/36 are for the left front speed sensor.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTE: When replacing the ABS and TRACTION actuator assembly, perform zero point calibration (Programming and Relearning).

PROCEDURE

1. READ VALUE OF TECHSTREAM (FRONT SPEED SENSOR)
(a) Connect Techstream to the DLC3.
(b) Start the engine.
(c) Select the Data List mode on Techstream.

ABS / VSC / TRAC:

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

HINT: There is tolerance of ±10% in the speedometer indication.

NG -- INSPECT FRONT SPEED SENSOR
OK -- Continue to next step.
2. INSPECT SPEED SENSOR AND SENSOR ROTOR SERRATIONS

(a) INSPECTION USING OSCILLOSCOPE
(1) Connect the oscilloscope to terminals FR+ - FR- or FL+ - FL- of the skid control ECU.
(2) Drive the vehicle at about 19 mph (30 km/h), and check the signal waveform.
OK:
A waveform as shown in the figure should be output.

- As vehicle speed (wheel revolution speed) increases, a cycle 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 the speed sensor rotor's scratches, looseness or foreign matter attached to it.

NG -- INSPECT FRONT SPEED SENSOR
OK -- REPLACE ABS AND TRACTION ACTUATOR ASSEMBLY
3. INSPECT FRONT SPEED SENSOR

(a) Make sure that there is no looseness at the locking part and connecting part of connectors.
(b) Disconnect the speed sensor connectors.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
LH

(d) Measure the resistance according to the value(s) in the table below.
Standard resistance:
LH

NOTE: Check the speed sensor signal after replacement (Test Mode Procedure).

NG -- REPLACE FRONT SPEED SENSOR
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (FRONT SPEED SENSOR - SKID CONTROL ECU)

(a) Disconnect the skid control ECU connector and the front speed sensor connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
LH

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. INSPECT SPEED SENSOR AND SENSOR ROTOR SERRATIONS

(a) INSPECTION USING OSCILLOSCOPE
(1) Connect the oscilloscope to terminals FR+ - FR- or FL+ - FL- of the skid control ECU.
(2) Drive the vehicle at about 19 mph (30 km/h), and check the signal waveform.
OK:
A waveform as shown in the figure should be output.

- As vehicle speed (Wheel revolution speed) increases, a cycle 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 the speed sensor rotor's scratches, looseness or foreign matter attached to it.

NG -- INSPECT FRONT SPEED SENSOR INSTALLATION
OK -- REPLACE ABS AND TRACTION ACTUATOR ASSEMBLY
6. INSPECT FRONT SPEED SENSOR INSTALLATION

(a) Check the speed sensor installation.
OK:
The installation bolt is tightened properly.
There is no clearance between the sensor and the front steering knuckle.

NOTE: Check the speed sensor signal after replacement (Test Mode Procedure).

Torque: 8.0 Nm (82 kgf-cm, 71 in-lbf)
NG -- REPLACE FRONT SPEED SENSOR
OK -- Continue to next step.
7. INSPECT FRONT SPEED SENSOR TIP
(a) Remove the front speed sensor (Removal).
(b) Check the sensor tip.
OK:
No scratches or foreign matter on the sensor tip.

NOTE: Check the speed sensor signal after cleaning / replacement (Test Mode Procedure).

NG -- CLEAN OR REPLACE FRONT SPEED SENSOR
OK -- Continue to next step.
8. INSPECT SPEED SENSOR ROTOR

(a) Remove the drive shaft assembly.
(b) Check the sensor rotor serrations.
OK:
No scratches, missing teeth or foreign matter on the rotors.

HINT: If there is foreign matter in the rotor, remove it and check the output waveform after reassembly.

NOTE: Check the speed sensor signal after cleaning / replacement (Test Mode Procedure).

NG -- REPLACE OUTBOARD JOINT SHAFT ASSEMBLY (SPEED SENSOR ROTOR)
OK -- REPLACE ABS AND TRACTION ACTUATOR ASSEMBLY