C1271

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C0200/31,C0205/32,C1271/71,C1272/72: Front Speed Sensor RH Circuit

DESCRIPTION

The speed sensor detects wheel speed and sends the appropriate signals to the ECU. These signals are used to control the ABS system. This speed sensor contains a sensor IC, which consists of 2 MREs (Magnetic Resistance Element). The speed sensor rotor, which consists of 48 sets of N and S poles that are arranged in a circle, is integrated with the inner race of the hub bearing.

To detect the rotation direction, the output waves are used to determine the relationship of the pulses that are generated by 2 MREs. Upon receiving this signal, the sensor IC outputs a forward or backward wave to the ECU.

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.

WIRING DIAGRAM

INSPECTION PROCEDURE

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

PROCEDURE

1. CHECK WIRE HARNESS (MOMENTARY INTERRUPTION)

(a) Using the 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 -- REPAIR OR REPLACE HARNESS OR CONNECTOR (SPEED SENSOR CIRCUIT)
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (FRONT SPEED SENSOR)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch ON (IG).

(c) Select the Data List mode on the Techstream.

ABS / VSC / TRAC:

(d) Check that the speed value output from the speed sensor displayed on the Techstream and the speed value displayed on the speedometer are almost the same 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.

ABS / VSC / TRAC:

(e) Check that the sensor signal conforms to the wheel direction.

OK:

The wheel direction is displayed.

NG -- INSPECT FRONT SPEED SENSOR INSTALLATION
OK -- Continue to next step.

3. PERFORM TEST MODE (SIGNAL CHECK)

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Perform sensor signal check in "TEST MODE PROCEDURE" Test Mode Procedure.

OK:

All Test Mode DTCs are erased.

NG -- INSPECT FRONT SPEED SENSOR INSTALLATION
OK -- Continue to next step.

4. RECONFIRM DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Turn the power switch ON (IG).

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

(d) Check if the same DTCs are recorded Reading and Clearing Diagnostic Trouble Codes.

Result

OK:

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

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

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

6. INSPECT FRONT 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/replacement Test Mode Procedure.

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

7. CHECK WIRE HARNESS (FRONT SPEED SENSOR WIRE)

(a) Disconnect the t1 sensor wire.

(b) Disconnect the m1 sensor wire.

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

Standard resistance:

for RH
for LH

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

NG -- REPLACE SKID CONTROL SENSOR WIRE
OK -- Continue to next step.

8. CHECK WIRE HARNESS (SKID CONTROL ECU - FRONT SPEED SENSOR)

(a) Disconnect the A13 and A15 ECU connectors.

(b) Disconnect the t1 sensor connector.

(c) Disconnect the m1 sensor connector.

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

Standard resistance:

for RH
for LH

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

9. CHECK SKID CONTROL ECU (SENSOR INPUT VOLTAGE)

(a) Reconnect the A13 and A15 ECU connectors.

(b) Disconnect the t1 sensor connector.

(c) Disconnect the m1 sensor connector.

(d) Turn the power switch ON (IG).

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

Standard voltage:

NG -- REPLACE SKID CONTROL ECU Removal
OK -- Continue to next step.

10. RECONFIRM DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Turn the power switch ON (READY).

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

(d) Check if the same DTCs are recorded Reading and Clearing Diagnostic Trouble Codes.

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

Result

HINT
If troubleshooting has been carried out according to the "PROBLEM SYMPTOMS TABLE", refer back to the table and proceed to the next step Problem Symptoms Table.

B -- REPLACE FRONT SPEED SENSOR

A -- END

11. REPLACE FRONT SPEED SENSOR

(a) Replace the front speed sensor Removal.

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

NEXT -- Continue to next step.

12. RECONFIRM DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Turn the power switch ON (READY).

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

(d) Check if the same DTCs are recorded Reading and Clearing Diagnostic Trouble Codes.

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

Result

HINT
If troubleshooting has been carried out according to the "PROBLEM SYMPTOMS TABLE", refer back to the table and proceed to the next step Problem Symptoms Table.

B -- END
A -- Continue to next step.

13. INSPECT SPEED SENSOR ROTOR

(a) Remove the speed sensor rotor.

(b) Check the sensor rotor.

OK:

No scratches, oil, or foreign matter on the rotors.

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

NG -- CLEAN OR REPLACE SPEED SENSOR ROTOR

OK -- REPLACE SKID CONTROL ECU Removal