C1401

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C1401,C1402: Front Speed Sensor RH Malfunction

DESCRIPTION

The speed sensor detects the wheel speed and sends the appropriate signals to the skid control ECU. These signals are used for the ABS control system. This speed sensor contains a sensor IC, which consists of 2 MREs (Magnetic Resistance Elements). The speed sensor rotor, which consists of 48 sets of N and S poles 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 the 2 MREs. Upon receiving this signal, the sensor IC outputs a forward or backward waveform to the ECU.

HINT
- DTC C1401 is for the front speed sensor RH.
- DTC C1402 is for the front speed sensor LH.
WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK FRONT SPEED SENSOR INSTALLATION

(a) Check the speed sensor installation (for 2WD).

OK:

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

(b) Check the speed sensor installation (for 4WD).

OK:

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

The installation bolt is tightened properly.

Torque
8.5 N*m (87 kgf*cm, 75 in.*lbf)

Result:

D -- INSTALL FRONT SPEED SENSOR CORRECTLY (for 4WD)

C -- INSTALL FRONT SPEED SENSOR CORRECTLY (for 2WD)

B -- READ VALUE USING TECHSTREAM (FRONT SPEED SENSOR)
A -- Continue to next step.

2. CHECK FRONT SPEED SENSOR TIP

(a) Remove the front speed sensor Removal.

(b) Check the speed sensor tip.

OK:

No scratches, oil, or foreign matter on the sensor tip.

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

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

3. CHECK FRONT SPEED SENSOR ROTOR

(a) Remove the front speed sensor rotor Removal.

(b) Check the speed sensor rotor.

OK:

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

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

HINT
The front speed sensor rotor is incorporated into the front axle hub sub-assembly.

If the front speed sensor rotor needs to be replaced, replace it together with the front axle hub sub-assembly.

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

4. READ VALUE USING TECHSTREAM (FRONT SPEED SENSOR)

(a) Install the front speed sensor and the front speed sensor rotor.

(b) Connect the Techstream to the DLC3.

(c) Start the engine.

(d) Select the Data List on the Techstream Data List / Active Test.

ABS/VSC/TRAC

ABS/VSC/TRAC:

(e) Check the speed value output from the speed sensor displayed on the Techstream.

HINT
Factors that affect the indicated vehicle speed include tire size, tire inflation, and tire wear. The speed indicated on the speedometer has an allowable margin of error. This can be tested using a speedometer tester (calibrated chassis dynamometer). For details about testing and the margin of error, see the reference chart Meter / Gauge System.

OK:

The speed value output from the speed sensor displayed on the Techstream is the similar speed as indicated on the speedometer.

Result:

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

HINT
- The front speed sensor rotor is incorporated into the front axle hub sub-assembly.
- If the front speed sensor rotor needs to be replaced, replace it together with the front axle hub sub-assembly.
- If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table.
C -- CHECK FOR INTERMITTENT PROBLEMS Electronic Circuit Inspection Procedure

B -- REPLACE FRONT SPEED SENSOR AND FRONT SENSOR SENSOR ROTOR
A -- Continue to next step.

5. REPLACE FRONT SPEED SENSOR

(a) Turn the engine switch off.

(b) Replace the front speed sensor Removal.

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

NEXT -- Continue to next step.

6. RECONFIRM DTC

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

(b) Start the engine.

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

(d) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.

Result: