Dtc C1401 Front Speed Sensor Rh Malfunction


DESCRIPTION

INSPECTION PROCEDURE

CHECK FRONT SPEED SENSOR INSTALLATION

INSPECT FRONT SPEED SENSOR TIP

INSPECT FRONT SPEED SENSOR ROTOR

READ VALUE USING INTELLIGENT TESTER (FR/FL WHEEL SPEED)

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 sensor detects the wheel speed and sends the appropriate signals to the skid control ECU. These signals are used for brake control.
The 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.
HINT:
When the connectors between the speed sensor and skid control ECU are connected, the following waveform is output.

Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Brake Control Dynamic Control Systems.Anti-Lock Brake System. Dtc C1401 Front Speed Sensor Rh Malfunction


DTC Code
DTC Detection Condition
Trouble Area
C1401
C1402
One of the following conditions is met:
  1. At a vehicle speed of 10 km/h (6 mph) or more, the 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 of less than 10 km/h (6 mph), 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 both front speed sensors are 0 km/h (0 mph) for 15 seconds or more.
  1. Front speed sensor RH/LH
  2. Front speed sensor rotor RH/LH
  3. Sensor installation
C1271
C1272
Stored only during test mode.
  1. Front speed sensor RH/LH
  2. Front speed sensor rotor RH/LH
  3. Sensor installation
HINT:
  1. DTCs C1401 and C1271 are for the front speed sensor RH.
  2. DTCs C1402 and C1272 are for the front speed sensor LH.

INSPECTION PROCEDURE

NOTICE:
Check the speed sensor signal after cleaning or replacement (LandCruiser RM00000452K011X.html).
1.CHECK FRONT SPEED SENSOR INSTALLATION

  1. Turn the ignition switch off.



    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Brake Control Dynamic Control Systems.Anti-Lock Brake System. Dtc C1401 Front Speed Sensor Rh Malfunction

  1. Check the speed sensor installation (LandCruiser RM000001B2H02BX.html).

    OK:
    There is no clearance between the sensor and the front steering knuckle.
    The installation bolt is tightened properly.
    Text in Illustration
    *1
    		Front Speed Sensor
    *a
    		No clearance
    *b
    		OK
    *c
    		NG


NG
INSTALL FRONT SPEED SENSOR CORRECTLY
OK


2.INSPECT FRONT SPEED SENSOR TIP

  1. Remove the front speed sensor (LandCruiser RM000001B2J024X.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.


NG
CLEAN OR REPLACE FRONT SPEED SENSOR
OK


3.INSPECT FRONT SPEED SENSOR ROTOR

  1. Remove the front axle with ABS rotor bearing assembly (LandCruiser RM0000016X6037X.html).

  1. Check the speed sensor rotor.

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


NG
CLEAN OR REPLACE FRONT SPEED SENSOR ROTOR
OK


4.READ VALUE USING INTELLIGENT TESTER (FR/FL WHEEL SPEED)

  1. Turn the ignition switch off.

  1. Connect the intelligent tester to the DLC3.

  1. Start the engine.

  1. Turn the intelligent tester on.

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

    ABS/VSC/TRC
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    FR Wheel Speed
    		Front wheel speed sensor RH reading/ Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph)
    		Actual wheel speed
    		No large fluctuations when driving at a constant speed.
    FL Wheel Speed
    		Front wheel speed sensor LH reading/ Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph)
    		Actual wheel speed
    		No large fluctuations when driving at a constant speed.

  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, refer to the reference chart (LandCruiser RM000002Z4Q040X.html).
    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).


NG
Go to step 5
OK

USE SIMULATION METHOD TO CHECK (LandCruiser RM000003YMJ00XX.html)

5.REPLACE FRONT SPEED SENSOR

  1. Replace the front speed sensor (LandCruiser RM000001B2J024X.html).


NEXT


6.RECONFIRM DTC

  1. Clear the DTC (LandCruiser RM0000046KV016X.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 output (LandCruiser RM0000046KV016X.html).

    Result
    Result
    		Proceed to
    DTC is not output
    		A
    DTC is output
    		B


B
REPLACE FRONT AXLE WITH ABS ROTOR BEARING ASSEMBLY (LandCruiser RM0000016X702VX.html)
A

END