Front Speed Sensor RH Circuit - Electronically Controlled Brake System

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE 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 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)

DESCRIPTION

The speed sensor detects wheel speed and sends the appropriate signals to the ECU. These signals are used to control the ABS control system. The front and rear rotors have 48 serrations, respectively.
When the rotors rotate, the magnetic field emitted by the permanent magnet in the speed sensor generates an 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 and C1272/72 can be deleted when the speed sensor sends a vehicle speed signal or the Test Mode ends. DTCs C1271/71 and C1272/72 are output only in the Test Mode.









HINT:
- DTC C0200/31 is for the right front speed sensor.
- DTC C0205/32 is for the left front speed sensor.
- The BRAKE warning light comes on when speed sensor malfunctions are detected in 2 or more wheels.

WIRING DIAGRAM





INSPECTION PROCEDURE
NOTE: When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration Initialization.

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)
(a) Using Techstream, check for any momentary interruption in the wire harness and connector corresponding to a DTC Check For Intermittent Problems.

ABS / VSC / TRAC:





OK:
There are no momentary interruptions.
HINT: Perform the above inspection before removing the sensor and connector.

NG -- CHECK WIRE HARNESS (SKID CONTROL ECU - FRONT SPEED SENSOR)
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (FRONT SPEED SENSOR)
(a) Check the Data List for proper functioning of the front speed sensor.

ABS / VSC / TRAC:





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.

3. CHECK SPEED SENSOR AND SENSOR ROTOR SERRATIONS




(a) Connect the oscilloscope to terminal FR+ and FR-, or FL+ and FL- of the skid control ECU.
(b) Drive the vehicle at approximately 30 km/h (19 mph), and check the signal waveform.
OK:
A waveform as shown should be output.
HINT:
- As the 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 deposited on it.

NG -- CHECK SPEED SENSOR AND SENSOR ROTOR SERRATIONS
OK -- REPLACE SKID CONTROL ECU
4. INSPECT FRONT SPEED SENSOR




(a) Disconnect the speed sensor connector.
(b) Measure the resistance of the sensors.
Standard resistance:
for LH






for RH






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

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

5. CHECK WIRE HARNESS (SKID CONTROL ECU - FRONT SPEED SENSOR)
(a) Disconnect the S7 and S10 ECU connectors.




(b) Disconnect the A3 and A4 sensor connectors.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:
for LH






for RH






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.

6. CHECK SPEED SENSOR AND SENSOR ROTOR SERRATIONS




(a) Connect the oscilloscope to terminals FR+ and FR-, or FL+ and FL- of the skid control ECU.
(b) Drive the vehicle at approximately 30 km/h (19 mph), and check the signal waveform.
OK:
A waveform as shown should be output.
HINT:
- As the 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 deposited on it.

NG -- INSPECT FRONT SPEED SENSOR INSTALLATION
OK -- REPLACE SKID CONTROL ECU
7. INSPECT FRONT SPEED SENSOR INSTALLATION




(a) Check the speed sensor installation.
OK:
The installation bolt is tightened properly and there is no clearance between the sensor and front steering knuckle.
Torque: 8.0 Nm (82 kgf-cm, 71 in-lbf)
NOTE: Check the speed sensor signal after the replacement Test Mode Procedure.

NG -- REPLACE FRONT SPEED SENSOR
OK -- REPLACE SKID CONTROL ECU