DTC    C1401    Front Speed Sensor RH Malfunction

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

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

DTC    C1402    Front Speed Sensor LH Malfunction

for Preparation Click here


DESCRIPTION

The speed sensor detects wheel speed and sends the appropriate signals to the skid control ECU. These signals are used for ABS control.
Speed sensor rotors have rows of alternating N and S magnetic poles, and their magnetic fields change when the rotors turn.
Each speed sensor detects that magnetic change and sends a pulse signal to the skid control ECU.

F100269E04


DTC Code
DTC Detection Condition
Trouble Area
C1401
C1402
Any of the following is detected:
  1. At a vehicle speed of 10 km/h (6 mph) or more, output voltage from one of the speed sensors is less than that from the other sensors for 15 seconds or more.
  2. At a vehicle speed less than 10 km/h (6 mph), output from one of the speed sensors is 0 km/h (0 mph) for 1 second or more.
  3. At a vehicle speed of 10 km/h (6 mph) or more, outputs from both front speed sensors are 0 km/h (0 mph) for 15 seconds or more.
  1. Front speed sensor RH/LH
  2. Speed sensor rotor
  3. Sensor installation
C1271
C1272
Detected only during Test Mode.
  1. Front speed sensor RH/LH
  2. Speed sensor rotor
  3. Sensor installation

HINT:
  1. DTC C1401 is for the front speed sensor RH.
  2. DTC C1402 is for the front speed sensor LH.


WIRING DIAGRAM


C168829E17


INSPECTION PROCEDURE

1.CHECK FRONT SPEED SENSOR INSTALLATION

  1. Turn the ignition switch off.



    C144929E16

  1. Check the speed sensor installation.

    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)



NG
INSTALL FRONT SPEED SENSOR CORRECTLY (Click here)
OK


2.INSPECT FRONT SPEED SENSOR TIP

  1. Remove the front speed sensor (Click here).

  1. 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 (Click here).



NG
CLEAN OR REPLACE FRONT SPEED SENSOR
OK


3.INSPECT FRONT SPEED SENSOR ROTOR

  1. Remove the front speed sensor rotor (Click here).

  1. 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 (Click here).

    HINT:
    If the front speed sensor rotor needs to be replaced, replace it together with the front drive outboard joint shaft assembly.



NG
CLEAN OR REPLACE FRONT SPEED SENSOR ROTOR
OK


4.READ VALUE USING INTELLIGENT TESTER (FRONT SPEED SENSOR)

  1. Install the front speed sensor and the front speed sensor rotor.

  1. Connect the intelligent tester to the DLC3.

  1. Start the engine.

  1. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

    ABS/VSC/TRC (Skid Control ECU) 
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    FR Wheel Speed
    		FR wheel speed sensor reading / min.: 0 km/h (0 mph), max.: 326 km/h (202 mph)
    		Actual wheel speed
    		Similar speed as indicated on speedometer
    FL Wheel Speed
    		FL wheel speed sensor reading /min.: 0 km/h (0 mph), max.: 326 km/h (202 mph)
    		Actual wheel speed
    		Similar speed as indicated on speedometer

  1. Check that there is no difference between the speed value output from the speed sensor displayed on the intelligent tester and the speed value displayed on the speedometer when driving the vehicle.

    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 (Click here).

    OK:
    The speed value output from the speed sensor displayed on the intelligent tester is the same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer).

    HINT:
    If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step (Click here).



NG
Go to step 5
OK

CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) (Click here)  

5.REPLACE FRONT SPEED SENSOR

  1. Turn the ignition switch off.

  1. Replace the front speed sensor (Click here).

    NOTICE:
    Check the speed sensor signal after replacement (Click here).


NEXT


6.RECONFIRM DTC

  1. Clear the DTCs (Click here).

  1. Start the engine.

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

  1. Check if the same DTC is recorded (Click here).

    Result:

    Result
    		Proceed to
    DTCs (C1401 and C1402) are not output
    		A
    DTCs (C1401 and/or C1402) are output
    		B

    NOTICE:
    Check the speed sensor signal after replacement (Click here).

    HINT:
    1. If the front speed sensor rotor needs to be replaced, replace it together with the front drive outboard joint shaft assembly.
    2. If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step (Click here).



B
REPLACE FRONT SPEED SENSOR ROTOR (Click here)
A

END