Dtc C1401 Front Speed Sensor Rh Malfunction

Brake. Yaris. Ncp93, 131
Brake Control Dynamic Control Systems. Yaris. Ncp93, 131

DESCRIPTION

INSPECTION PROCEDURE

CHECK FRONT SPEED SENSOR INSTALLATION

INSPECT FRONT SPEED SENSOR TIP

INSPECT FRONT AXLE HUB BEARING

READ VALUE USING TECHSTREAM (FRONT SPEED SENSOR)

REPLACE FRONT SPEED SENSOR

RECONFIRM DTC

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


DESCRIPTION

The speed sensors detect the wheel speeds and send appropriate signals to the skid control ECU. Speed sensor rotors have rows of alternating N and S magnetic poles, and their magnetic fields change as the rotors turn.
The speed sensors detect those magnetic changes and send pulse signals to the skid control ECU. The ECU monitors the wheel speeds through these pulse signals to control the ABS control system.
HINT:
When testing voltage, perform the test while the connector between the sensor and ECU is connected. Do not disconnect the connector between the sensor and ECU.

Yaris. Ncp93, 131.Brake Control Dynamic Control Systems.Anti-Lock Brake System (For Sedan). Dtc C1401 Front Speed Sensor Rh Malfunction


DTC NO.
DTC Detection Condition
Trouble Area
C1401
C1402
When any of the following is detected:
  1. At a vehicle speed of 10 km/h (6 mph) or more, the output speed signal from one of the speed sensors is equal to or less than 14% of that of one of other 3 sensors for 15 seconds or more.
  2. At a vehicle speed of 10 km/h (6 mph) or more, the 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, the outputs from 2 of the speed sensors are 0 km/h (0 mph) for 15 seconds or more.
  1. Front speed sensor RH/LH
  2. Front axle hub bearing RH/LH (speed sensor rotor)
  3. Sensor installation
C1271
C1272
Detected only during Test Mode.
  1. Front speed sensor RH/LH
  2. Front axle hub bearing RH/LH (speed sensor rotor)
  3. Sensor installation
HINT:
  1. DTC C1401 and C1271 are for the front speed sensor RH.
  2. DTC C1402 and C1272 are for the front speed sensor LH.

INSPECTION PROCEDURE

NOTICE:
Check the speed sensor signal after cleaning or replacement (YARIS_NCP93 RM000000XHT08HX.html).
1.CHECK FRONT SPEED SENSOR INSTALLATION

  1. Turn the ignition switch off.



    Yaris. Ncp93, 131.Brake Control Dynamic Control Systems.Anti-Lock Brake System (For Sedan). Dtc C1401 Front Speed Sensor Rh Malfunction

  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)
    Text in Illustration
    *1
    		Front Speed Sensor
    *a
    		No clearance
    *b
    		OK
    *c
    		NG


NG
INSTALL FRONT SPEED SENSOR CORRECTLY (YARIS_NCP93 RM000001BXU01HX.html)
OK


2.INSPECT FRONT SPEED SENSOR TIP

  1. Remove the front speed sensor (YARIS_NCP93 RM000001BXX01CX.html).

  1. Check the speed sensor tip.

    OK:
    No scratches, oil, or foreign matter on the sensor tip.
    NOTICE:
    If no damage to the speed sensor tip is found during this inspection, do not replace the speed sensor.

  1. Reinstall the front speed sensor (YARIS_NCP93 RM000001BXU01HX.html).



NG
CLEAN OR REPLACE FRONT SPEED SENSOR
OK


3.INSPECT FRONT AXLE HUB BEARING

  1. Remove the front axle hub bearing (YARIS_NCP93 RM000001IWM00OX.html).

  1. Check the speed sensor rotor.

    OK:
    No scratches, oil, or foreign matter on the rotors.
    HINT:
    If the front speed sensor rotor needs to be replaced, replace it together with the front axle hub bearing.

  1. Reinstall the front axle hub assembly (YARIS_NCP93 RM000001IWK00PX.html).



NG
CLEAN OR REPLACE FRONT AXLE HUB BEARING
OK


4.READ VALUE USING TECHSTREAM (FRONT SPEED SENSOR)

  1. Turn the ignition switch off.

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

  1. According to the display on the Techstream, read the Data List.

    ABS/VSC/TRAC
    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)
    		Vehicle stopped:
    0 km/h
    		When driving at constant speed: No large fluctuations
    FL Wheel Speed
    		FL wheel speed sensor reading /min.: 0 km/h (0 mph), max.: 326 km/h (202 mph)
    		Vehicle stopped:
    0 km/h
    		When driving at constant speed: No large fluctuations

  1. Check that there is no difference between the speed value output from the speed sensor displayed on the Techstream 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.
    OK:
    The speed value output from the speed sensor displayed on the Techstream 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 (YARIS_NCP93 RM000000XHN0AWX.html).


NG
Go to step 5
OK

CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) (YARIS_NCP93 RM000000UZ309WX.html)

5.REPLACE FRONT SPEED SENSOR

  1. Turn the ignition switch off.

  1. Replace the front speed sensor (YARIS_NCP93 RM000001BXX01CX.html).


NEXT


6.RECONFIRM DTC

  1. Clear the DTCs (YARIS_NCP93 RM000000XHV0BPX.html).

  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 (YARIS_NCP93 RM000000XHV0BPX.html).

    Result
    Result
    		Proceed to
    DTCs (C1401 and C1402) are not output
    		A
    DTCs (C1401 and/or C1402) are output
    		B
HINT:
If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step (YARIS_NCP93 RM000000XHN0AWX.html).


B
REPLACE FRONT AXLE HUB BEARING (YARIS_NCP93 RM000001IWK00PX.html)
A

END