Toyota Tundra Service Manual: Brake Pedal Load Sensing Switch OFF Stuck Malfunction (C1430,C1431)

Toyota Tundra Service Manual / Brake / Brake Control / Dynamic Control Systems / Vehicle Stability Control System / Brake Pedal Load Sensing Switch OFF Stuck Malfunction (C1430,C1431)

DESCRIPTION

The brake pedal load sensing switch turns on when the brake pedal is depressed with a force exceeding a predetermined level.

The skid control ECU uses this circuit to detect if the brake pedal is depressed or not.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1430

Brake Pedal Load Sensing Switch OFF Stuck Malfunction

Either of the following is detected:

  • With the stop light switch on, the brake pedal load sensing switch off, and the master cylinder pressure more than 6 MPa (61.2 kgf/cm2, 870 psi), the vehicle acceleration rate is less than -4 m/s2 for 1 second or more.
  • With the stop light switch on, the brake pedal load sensing switch off, and the master cylinder pressure more than 6 MPa (61.2 kgf/cm2, 870 psi), the vehicle speed is 0 km/h (0 mph) for 5 seconds or more.
  • Brake pedal load sensing switch (Brake pedal support assembly)
  • Brake pedal load sensing switch circuit

C1431

Brake Pedal Load Sensing Switch ON Stuck Malfunction

Either of the following is detected:

  • With the stop light switch off, the brake pedal load sensing switch on, and the master cylinder pressure less than 0.7 MPa (7.13 kgf/cm2, 101 psi), the vehicle acceleration rate is more than -0.8 m/s2 for 10 seconds or more. (Only when the engine is running and booster malfunctions are not detected.)
  • Condition which the brake pedal load sensing switch remains on while the vehicle speed increases from 0 km/h (0 mph) to 30 km/h (19 mph) occurs 3 times in succession.
  • Brake pedal load sensing switch (Brake pedal support assembly)
  • Brake pedal load sensing switch circuit

WIRING DIAGRAM

Refer to DTC C1429.

Click here

CAUTION / NOTICE / HINT

HINT:

When C1249, C1425 and/or C1426 is output together with C1430 and/or C1431, inspect and repair the trouble areas indicated by C1249, C1425 and/or C1426 first (Click here ), (Click here ), and/or (Click here ).

PROCEDURE

1.

READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH ASSEMBLY AND BRAKE PEDAL LOAD SENSING SWITCH)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Select the Data List using the Techstream.

Click here

ABS/VSC/TRAC

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Stop Light SW

Stop light switch assembly

ON or OFF

ON: Brake pedal depressed

OFF: Brake pedal released

-

Brake Pedal Load Sensing SW

Brake pedal load sensing switch

ON or OFF

ON: Brake pedal depressed beyond a specified point

OFF: Brake pedal not depressed beyond a specified point

-

(d) Check that the stop light switch display and brake pedal load sensing switch display observed on the Techstream change according to brake pedal operation.

OK:

The Techstream displays ON or OFF according to brake pedal operation.

(e) Slowly depress the brake pedal, and check when the stop light switch and brake pedal load sensing switch turn on.

OK:

First the stop light switch turns on, and then the brake pedal load sensing switch turns on.

Result

Proceed to

OK

A

NG (Turning on of the brake pedal load sensing switch is not confirmed.)

B

NG (The brake pedal load sensing switch turns on first.)

C
B

GO TO STEP 3

C

GO TO STEP 4

A

2.

RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Clear the DTCs.

Click here

(c) Turn the ignition switch off.

(d) Start the engine.

(e) Perform a road test.

(f) Check if the same DTC is output.

Click here

Result

Proceed to

DTCs C1430 and C1431 are not output.

A

DTCs C1430 and C1431 are output.

B
A

USE SIMULATION METHOD TO CHECK

B

REPLACE BRAKE ACTUATOR ASSEMBLY

3.

INSPECT BRAKE PEDAL SUPPORT ASSEMBLY

(a) Turn the ignition switch off.

(b) Inspect the brake pedal load sensing switch (brake pedal support assembly).

Click here

OK:

The brake pedal load sensing switch (brake pedal support assembly) is normal.

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPLACE BRAKE PEDAL SUPPORT ASSEMBLY

4.

CHECK BRAKE PEDAL AND STOP LIGHT SWITCH ASSEMBLY INSTALLATION

(a) Turn the ignition switch off.

(b) Check the brake pedal height.

Click here

(c) Check the stop light switch assembly installation.

Click here

OK:

The brake pedal height and stop light switch assembly installation are normal.

OK

REPLACE BRAKE PEDAL SUPPORT ASSEMBLY

NG

ADJUST BRAKE PEDAL OR STOP LIGHT SWITCH ASSEMBLY

    Open or Short in Brake Pedal Load Sensing Switch (C1429)

    Steering Angle Sensor Power Source Voltage Malfunction (C1432)

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