Diagnostic trouble code C1253 Land Cruiser

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (MOTOR RELAY)

RECONFIRM DTC

INSPECT SKID CONTROL ECU (+BM TERMINAL)

INSPECT SKID CONTROL ECU (GND TERMINAL)

RECONFIRM DTC

DTC C1253/53 Pump Motor Relay Malfunction

Description

The motor relay (semiconductor relay) is built into the master cylinder solenoid and drives the pump motor based on a signal from the skid control ECU.

DTC Code DTC Detection Condition Trouble Area
C1253/53 There is a motor system circuit (motor input circuit) malfunction.
  1. Hydraulic brake booster pump motor
  2. Hydraulic brake booster pump motor circuit

Wiring diagram

Diagnostic trouble code C1253 Land Cruiser Wiring diagram

Inspection procedure

NOTICE:

When replacing the hydraulic brake booster assembly (master cylinder solenoid), perform zero point calibration .

1.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (MOTOR RELAY)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and turn the intelligent tester on.

  1. Start the engine.

  1. Enter the following menus: Chassis / ABS/VSC/TRC / Active Test.

    ABS/VSC/TRC
    Tester Display Test Part Control Range Diagnostic Note
    Motor Relay Motor relay Relay ON/OFF An operation sound of the motor can be heard.

  1. Check the operation sound of the motor individually when operating it with the intelligent tester.

    OK:

    The operation sound of the motor can be heard.

  NG  
Go to step 3
 
OK  
   

2.RECONFIRM DTC

  1. Clear the DTC .

  1. Turn the ignition switch off.

  1. Depress the brake pedal more than 20 times.

  1. Turn the ignition switch to ON.

  1. Wait until the pump motor stops.

  1. Depress the brake pedal several times until the pump motor turns on. (Procedure A)

  1. Wait until the pump stops. (Procedure B)

  1. Repeat the above steps (procedure A and B) 3 more times.

  1. Check if the same DTC is output .

    HINT:

    Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

    Result
    Result Proceed to
    DTC is not output A
    DTC is output LHD B
    RHD C
  B  
REPLACE MASTER CYLINDER SOLENOID
 
  C  
REPLACE MASTER CYLINDER SOLENOID
 
A  
   
USE SIMULATION METHOD TO CHECK

3.INSPECT SKID CONTROL ECU (+BM TERMINAL)

Diagnostic trouble code C1253 Land Cruiser. Disconnect the A24 and A25 skid control ECU connectors.

  1. Disconnect the A24 and A25 skid control ECU connectors.

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

    Standard Voltage:

    Tester Connection Condition Specified Condition
    A24-2 (+BM1) - Body ground Always 11 to 14 V
    A25-2 (+BM2) - Body ground Always 11 to 14 V
  NG  
REPAIR OR REPLACE HARNESS OR CONNECTOR
 
OK  
   

4.INSPECT SKID CONTROL ECU (GND TERMINAL)

Diagnostic trouble code C1253 Land Cruiser. Measure the resistance according to the value(s) in the table below.

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

    Standard Resistance:

    Tester Connection Condition Specified Condition
    A24-1 (GND1) - Body ground Always Below 1 ?
    A24-32 (GND2) - Body ground Always Below 1 ?
    A25-4 (GND3) - Body ground Always Below 1 ?
  NG  
REPAIR OR REPLACE HARNESS OR CONNECTOR
 
OK  
   

5.RECONFIRM DTC

  1. Clear the DTC .

  1. Turn the ignition switch off.

  1. Depress the brake pedal more than 20 times.

  1. Turn the ignition switch to ON.

  1. Wait until the pump motor stops.

  1. Depress the brake pedal several times until the pump motor turns on. (Procedure A)

  1. Wait until the pump stops. (Procedure B)

  1. Repeat the above steps (procedure A and B) 3 more times.

  1. Check if the same DTC is output .

    HINT:

    Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

    Result
    Result Proceed to
    DTC is not output A
    DTC is output LHD B
    RHD C
  B  
REPLACE MASTER CYLINDER SOLENOID
 
  C  
REPLACE MASTER CYLINDER SOLENOID
 
A  
   
USE SIMULATION METHOD TO CHECK