Lexus IS250 · Service Manual BRAKE

C1267/67

Diagnostic trouble codes

DESCRIPTION

The brake pedal load sensing switch is turned on when the brake pedal is depressed with force exceeding a predetermined level.
The skid control ECU detects if the brake pedal is depressed or not via this circuit.
DTC No.
 DTC Detection Condition
 Trouble Area
C1267/67
 When any of the following is detected:
  1. An open or short in the brake pedal load sensing switch continues for 0.3 seconds or more.
  2. Immediately after the engine switch is turned on (IG), the brake pedal load sensing switch is ON and the stop light switch is OFF for 10 seconds or more.
  3. While the vehicle speed changes from 0 mph (0 km/h) to 18 mph (30 km/h), the condition that the brake pedal load sensing switch remains ON occurs 5 times in succession.
  4. With the stop light switch ON, the brake pedal load sensing switch OFF, and the master cylinder pressure 6 Mpa or more, the deceleration is 0.4 G or more for 1 second or more.
  5. With the stop light switch ON, the brake pedal load sensing switch OFF, and the master cylinder pressure 6 Mpa or more, the vehicle speed is 0 mph (0 km/h) for 5 seconds or more.
  1. Brake pedal load sensing switch
  2. Brake pedal load sensing switch circuit

WIRING DIAGRAM

C114549E01

INSPECTION PROCEDURE

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

HINT:
If C1249/49 is output, repair it before repairing C1267/67 based on the flow chart below.


1. READ VALUE OF INTELLIGENT TESTER (BRAKE PEDAL LOAD SENSING SWITCH)

  1. Connect the intelligent tester to the DLC3.

  1. Start the engine.

  1. Select the Data List mode on the intelligent tester.

    ABS / VSC: 
    Item (Display)
    		 Measurement Item / Range (Display)
    		 Normal Condition
    Brake Pedal Load Sensing SW
    		 Brake pedal load sensing switch / ON or OFF
    		 ON : Depressed brake pedal
    OFF : Released brake pedal

  1. Read the value of the brake pedal load sensing switch displayed on the intelligent tester when depressing and releasing the brake pedal.

    OK:
    Condition
    		 Display
    Brake pedal depressed
    		 ON
    Brake pedal released
    		 OFF



OK
Go to step 4
NG


2. INSPECT BRAKE PEDAL LOAD SENSING SWITCH
C106569E08
C106568E02

NOTICE:
  1. Do not remove the brake pedal load sensing switch from the brake pedal sub-assembly.
  2. When there is a malfunction in the brake pedal load sensing switch, replace the brake pedal sub-assembly.

  1. Turn the engine switch off.

  1. Disconnect the brake pedal load sensing switch connector.

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

    Standard resistance:
    Tester Connection
    		 Condition
    		 Specified Condition
    2 (FSW+) - 1 (GND)
    		 Brake pedal depressed (OFF)
    		 0.9 to 1.1 kΩ
    2 (FSW+) - 1 (GND)
    		 Brake pedal released (ON)
    		 192 to 234 Ω



NG
REPLACE BRAKE PEDAL SUB-ASSEMBLY (BRAKE PEDAL LOAD SENSING SWITCH)
OK


3. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE PEDAL LOAD SENSING SWITCH)

  1. C110685E03
    Disconnect the skid control ECU connector.

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

    Standard resistance:
    Tester Connection
    		 Condition
    		 Specified Condition
    A14-7 (FSW+) - A23-2 (FSW+)
    		 Always
    		 Below 1 Ω
    A14-7 (FSW+) - Body ground
    		 Always
    		 10 kΩ or higher
    A23-1 (GND) - Body ground
    		 Always
    		 Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4. RECONFIRM DTC

  1. Reconnect the skid control ECU connector and the brake pedal load sensing switch connector.

  1. Clear the DTC (Click here).

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

    Result:
    Condition
    		 Proceed to
    DTC (C1267/67) is not output
    		 A
    DTC (C1267/67) is output
    		 B



B
REPLACE BRAKE ACTUATOR ASSEMBLY
A

USE SIMULATION METHOD TO CHECK


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