DTC    C1405    Open or Short in Front Speed Sensor RH Circuit

DTC    C1406    Open or Short in Front Speed Sensor LH Circuit

for Preparation Click here


DESCRIPTION

Refer to DTCs C1401 and C1402 (Click here).

DTC Code
DTC Detection Condition
Trouble Area
C1405
C1406
Either of the following is detected:
  1. An open in the speed sensor signal circuit continues for 0.5 seconds or more.
  2. With the IG1 terminal voltage 9.5 V or more, the sensor power supply voltage decreases for 0.5 seconds or more.
  1. Front speed sensor RH/LH
  2. Speed sensor circuit
  3. Brake actuator assembly (Skid control ECU)

HINT:
  1. DTC C1405 is for the front speed sensor RH.
  2. DTC C1406 is for the front speed sensor LH.


WIRING DIAGRAM

Refer to DTCs C1401 and C1402 (Click here).

INSPECTION PROCEDURE

NOTICE:
When replacing the brake actuator assembly, perform zero point calibration (Click here).

1.CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

  1. Using the intelligent tester, check for any momentary interruption in the wire harness and connector corresponding to the DTC (Click here).

    ABS/VSC/TRC 
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    FR Speed Open
    		FR speed sensor open detection / ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    FL Speed Open
    		FL speed sensor open detection / ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-

    OK:
    There are no momentary interruptions.

    HINT:
    Perform the above inspection before removing the sensor and connector.



NG
Go to step 4
OK


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

  1. Turn the ignition switch off.

  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 intelligent tester is the same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer).



NG
Go to step 4
OK


3.RECONFIRM DTC

  1. Turn the ignition switch off.

  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 (C1405 and C1406) are not output
    		A
    DTCs (C1405 and/or C1406) 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 (Click here).



B
REPLACE BRAKE ACTUATOR ASSEMBLY (Click here)
A

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

4.CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - FRONT SPEED SENSOR)


    C197056E01

  1. Turn the ignition switch off.
    Text in illustration 
    *1
    		Front view of wire harness connector
    (to Skid Control ECU)
    *2
    		Front view of wire harness connector
    (to Front Speed Sensor)

  1. Make sure that there is no looseness at the locking part and the connecting part of the connectors.

  1. Disconnect the skid control ECU connector and the front speed sensor connector.

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

    Standard Resistance (for LHD):
    for RH:
    Tester Connection
    		Condition
    		Specified Condition
    A16-7 (FR+) - A11-2 (FR+)
    		Always
    		Below 1 Ω
    A16-7 (FR+) - Body ground
    		Always
    		10 kΩ or higher
    A16-6 (FR-) - A11-1 (FR-)
    		Always
    		Below 1 Ω
    A16-6 (FR-) - Body ground
    		Always
    		10 kΩ or higher
    for LH:
    Tester Connection
    		Condition
    		Specified Condition
    A16-19 (FL+) - A4-2 (FL+)
    		Always
    		Below 1 Ω
    A16-19 (FL+) - Body ground
    		Always
    		10 kΩ or higher
    A16-18 (FL-) - A4-1 (FL-)
    		Always
    		Below 1 Ω
    A16-18 (FL-) - Body ground
    		Always
    		10 kΩ or higher


    Standard Resistance (for RHD):
    for RH:
    Tester Connection
    		Condition
    		Specified Condition
    A17-7 (FR+) - A11-2 (FR+)
    		Always
    		Below 1 Ω
    A17-7 (FR+) - Body ground
    		Always
    		10 kΩ or higher
    A17-6 (FR-) - A11-1 (FR-)
    		Always
    		Below 1 Ω
    A17-6 (FR-) - Body ground
    		Always
    		10 kΩ or higher
    for LH:
    Tester Connection
    		Condition
    		Specified Condition
    A17-19 (FL+) - A4-2 (FL+)
    		Always
    		Below 1 Ω
    A17-19 (FL+) - Body ground
    		Always
    		10 kΩ or higher
    A17-18 (FL-) - A4-1 (FL-)
    		Always
    		Below 1 Ω
    A17-18 (FL-) - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.INSPECT SKID CONTROL ECU (SENSOR INPUT)


    C197057E01

  1. Reconnect the skid control ECU connector.
    Text in illustration 
    *1
    		Front view of wire harness connector
    (to Front Speed Sensor)

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    for RH:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A11-2 (FR+) - Body ground
    		Ignition switch ON
    		8 to 14 V
    for LH:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A4-2 (FL+) - Body ground
    		Ignition switch ON
    		8 to 14 V

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

    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
REPLACE BRAKE ACTUATOR ASSEMBLY (Click here)
OK

REPLACE FRONT SPEED SENSOR (Click here)