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DTC    C1246/46    Master Cylinder Pressure Sensor Malfunction

DTC    C1281/81    Master Cylinder Pressure Sensor Output Malfunction (Test Mode DTC)

DTC    C1364/61    Wheel Cylinder Pressure Sensor Malfunction

for Preparation Click here


DESCRIPTION

The regulator pressure sensor and the wheel cylinder pressure sensor are built into the brake actuator, and measure the regulator pressure and the wheel cylinder pressure sent to the skid control ECU.
DTC C1281/81 will be cleared when the regulator pressure sensor sends a regulator pressure signal or when Test Mode ends. DTC C1281/81 is output only in Test Mode.

DTC Code
INF Code
DTC Detection Condition
Trouble Area
C1246/46
201
Sensor supply voltage (VCM1) is 4.75 V or less, or 5.25 V or more for 0.05 seconds.
Brake booster with master cylinder (Skid control ECU or brake actuator)
↑
202
Regulator pressure sensor output voltage (Preg) is less than 8%, or 90.3% or more (less than 0.4 V, or 4.52 V or more) of sensor supply voltage (VCM1) for 0.05 seconds or more.
↑
↑
203
When not under braking, the regulator pressure sensor output voltage is 0.2 V or less or 0.88 V or more for 3 seconds or more.
↑
↑
204
Either of the following is detected:
  1. The regulator pressure sensor output voltage does not correspond with stroke sensor and the readings remain out of specification for 0.5 to 5 seconds or more continuously.
    (The stroke sensor may be malfunctioning.)
  2. The regulator pressure sensor output voltage does not correspond with wheel cylinder pressure sensor and the outputs remain out of specification for 0.5 to 5 seconds or more continuously.
    (May be output with INF code 424.)
  1. Brake pedal stroke sensor
  2. Brake booster with master cylinder (Skid control ECU or brake actuator)
↑
207
Fluctuation of regulator pressure sensor output is out of specification (the difference between the present value and last value is 15 MPa (153.0 kgf/cm2, 2176 psi) or more) for 0.1 seconds or more.
Brake booster with master cylinder (Skid control ECU or brake actuator)
C1364/61
421
Sensor supply voltage 1 (VCM1) is 4.75 V or less, or 5.25 V or more for 0.05 seconds or more.
Brake booster with master cylinder (Skid control ECU or brake actuator)
↑
422
Wheel cylinder pressure sensor output voltage (Pfront) is less than 8%, or 90.3% or more (less than 0.4 V, or 4.52 V or more) of sensor supply voltage (VCM1) for 0.05 seconds or more.
↑
↑
423
When not under braking, the wheel cylinder pressure sensor output voltage is 0.2 V or less or 0.88 V or more for 0.1 to 3 seconds or more.
↑
↑
424
The wheel cylinder pressure sensor output voltage does not correspond with regulator pressure sensor and the outputs remain out of specification for 0.5 to 5 seconds or more continuously.
(May be output with INF code 204.)
↑
↑
426
Fluctuation of wheel cylinder pressure sensor output is out of specification (the difference between the present value and last value is 15 MPa (153.0 kgf/cm2, 2176 psi) or more) for 0.1 seconds or more.
↑
C1281/81
-
Detected only during Test Mode.
  1. Stop light switch
  2. Regulator pressure sensor

INSPECTION PROCEDURE

NOTICE:
When replacing the brake booster with master cylinder (skid control ECU or brake actuator), perform initialization, calibration of the linear solenoid valve and emergency brake signal learning (Click here).

1.CHECK STOP LIGHT SWITCH INSTALLATION

  1. Check the protrusion of the rod (Click here).

    OK:
    Stop light switch is installed properly.

    HINT:
    If the stop light switch is not installed properly, adjust the protrusion of the rod before proceeding to the next step.



NG
ADJUST PROTRUSION OF ROD (Click here)
OK


2.READ VALUE USING INTELLIGENT TESTER (REGULATOR PRESSURE SENSOR)

  1. Set a pedal effort gauge and LSPV gauge to rear wheel (Click here).

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Select the Data List on the intelligent tester (Click here).

    ABS/VSC/TRC 
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    Regulator Pressure Sensor Output
    		Regulator pressure sensor output / Min.: 0 V, Max.: 5 V
    		When brake pedal released:
    0.1 to 0.9 V
    		Reading increases when brake pedal is depressed

  1. Check the output value of the regulator pressure sensor as the brake pedal is depressed.

    Standard Voltage:

    Brake Effort
    (N (kgf, lbf))
    		Regulator Pressure Sensor Output
    (V)
    		Rear Right Wheel Hydraulic Pressure
    (MPa (kgf/cm2, psi))
    		Rear Left Wheel Hydraulic Pressure
    (MPa (kgf/cm2, psi))
    100 (10, 22.5)
    		1.48 to 2.28
    		4.8 to 8.8 (49.0 to 89.7, 697 to 1276)
    		4.8 to 8.8 (49.0 to 89.7, 697 to 1276)
    200 (20, 45.0)
    		3.30 to 4.10
    		13.8 to 17.8 (140.8 to 181.5, 2002 to 2581)
    		13.8 to 17.8 (140.8 to 181.5, 2002 to 2581)


    Result:

    Result
    		Proceed to
    OK
    		A
    NG (for LHD)
    		B
    NG (for RHD)
    		C



B
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)

C
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)
A


3.READ VALUE USING INTELLIGENT TESTER (WHEEL CYLINDER PRESSURE SENSOR)

  1. Set a LSPV gauge to front wheel (Click here).

  1. Select the Data List on the intelligent tester (Click here).

    ABS/VSC/TRC 
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    Wheel Cylinder Pressure Sensor
    		Wheel cylinder pressure sensor / Min.: 0 V, Max.: 5 V
    		When brake pedal released:
    0.1 to 0.9 V
    		Reading increases when brake pedal is depressed

  1. Check the output value of the wheel cylinder pressure sensor at each hydraulic pressure during electronically controlled brake system control.

    Standard Voltage:
    for Front Wheel Cylinder Pressure Sensor LH:

    Hydraulic Pressure
    (MPa (kgf/cm2, psi))
    		Wheel Cylinder Pressure Sensor
    (V)
    2.0 (20.4, 290)
    		0.53 to 1.33
    5.0 (51.0, 725)
    		1.12 to 1.92
    7.0 (71.4, 1015)
    		1.52 to 2.32
    10.0 (102.0, 1451)
    		2.14 to 2.94
    for Front Wheel Cylinder Pressure Sensor RH:

    Hydraulic Pressure
    (MPa (kgf/cm2, psi))
    		Wheel Cylinder Pressure Sensor
    (V)
    2.0 (20.4, 290)
    		0.53 to 1.33
    5.0 (51.0, 725)
    		1.12 to 1.92
    7.0 (71.4, 1015)
    		1.52 to 2.32
    10.0 (102.0, 1451)
    		2.14 to 2.94


    Result:

    Result
    		Proceed to
    OK
    		A
    NG (for LHD)
    		B
    NG (for RHD)
    		C



B
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)

C
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)
A


4.READ VALUE USING INTELLIGENT TESTER (BRAKE PEDAL STROKE SENSOR AND PRESSURE SENSOR COMPARISON)

  1. Set a pedal effort gauge and LSPV gauge to front and rear wheel (Click here).

  1. Select the Data List on the intelligent tester (Click here).

    ABS/VSC/TRC 
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    Stroke Sensor
    		Brake pedal stroke sensor / Min.: 0 V, Max.: 5 V
    		When brake pedal released: 0.65 to 1.35 V
    		Reading increases when brake pedal is depressed
    Stroke Sensor2
    		Brake pedal stroke sensor 2 / Min.: 0 V, Max.: 5 V
    		When brake pedal released: 3.65 to 4.35 V
    		Reading decreases when brake pedal is depressed
    Regulator Pressure Sensor Output
    		Regulator pressure sensor output / Min.: 0 V, Max.: 5 V
    		When brake pedal released:
    0.1 to 0.9 V
    		Reading increases when brake pedal is depressed
    Wheel Cylinder Pressure Sensor
    		Wheel cylinder pressure sensor / Min.: 0 V, Max.: 5 V
    		When brake pedal released:
    0.1 to 0.9 V
    		Reading increases when brake pedal is depressed

  1. Check the output value of the brake pedal stroke sensor as the brake pedal is depressed.

    Standard Voltage:

    Brake Effort
    (N (kgf, lbf))
    		Stroke Sensor
    (V)
    		Stroke Sensor2
    (V)
    		Regulator Pressure Sensor Output
    (V)
    		Wheel Cylinder Pressure Sensor
    (V)
    100 (10, 22.5)
    		1.07 to 1.77
    		3.23 to 3.93
    		1.48 to 2.28
    		1.28 to 2.08
    200 (20, 45.0)
    		1.45 to 2.15
    		2.85 to 3.55
    		3.30 to 4.10
    		2.85 to 3.65


    Result:

    Result
    		Proceed to
    OK
    		A
    NG (for LHD)
    		B
    NG (for RHD)
    		C



B
REPLACE BRAKE PEDAL STROKE SENSOR (Click here)

C
REPLACE BRAKE PEDAL STROKE SENSOR (Click here)
A


5.RECONFIRM DTC

  1. Turn the power switch off.

  1. Clear the DTCs (Click here).

  1. Perform a road test.

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

    Result:

    Result
    		Proceed to
    DTCs (C1246/46 and C1364/61) are not output
    		A
    DTCs (C1246/46 and/or C1364/61) are output (for LHD)
    		B
    DTCs (C1246/46 and/or C1364/61) are output (for RHD)
    		C



B
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)

C
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)
A

CHECK FOR INTERMITTENT PROBLEMS (Click here)