Brake Pedal Load Sensing Switch - Vehicle Stability Control System

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1267/28: Brake Pedal Load Sensing Switch

DTC C1267/28 - Brake Pedal Load Sensing Switch

DESCRIPTION

The skid control ECU detects if the brake pedal is depressed.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTE: When replacing the VSC actuator assembly, perform zero point calibration Programming and Relearning.

PROCEDURE

1. CHECK TERMINAL VOLTAGE (BOOSTER PEDAL MICRO SWITCH)




(a) Disconnect A20 booster connector.
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





NG -- CHECK HARNESS AND CONNECTOR (BOOSTER PEDAL MICRO SWITCH - SKID CONTROL ECU)
OK -- Continue to next step.

2. INSPECT BOOSTER PEDAL MICRO SWITCH





(a) When using an oscilloscope:
(1) Connect the oscilloscope between terminals 1 (PSNO) and 5 (STS), 2 (PSNC) and 5 (STS) of the brake booster with connector being connected.
(2) Turn the ignition switch to ON.
(3) Check the signal waveform while the brake pedal is depressed and released.
OK:
Signal waveform changes as shown in the illustration.





(b) When not using an oscilloscope:
(1) Disconnect the A20 booster connector.
(2) Turn the ignition switch to ON.
(3) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





NG -- REPLACE BRAKE BOOSTER ASSEMBLY
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (BOOSTER PEDAL MICRO SWITCH - SKID CONTROL ECU)




(a) Confirm that the skid control ECU connector and brake booster connector are properly connected.
(b) Disconnect the A19 ECU connector.
(c) Disconnect the A20 booster connector.
(d) Inspect both the connector case and the terminal for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE VSC ACTUATOR ASSEMBLY