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DTC    C1A4A    Skid Control Buzzer Circuit

for Preparation Click here


DESCRIPTION

The driving support ECU sends a sounding signal to the brake booster with master cylinder (skid control ECU) to sound the skid control buzzer.

DTC Code
DTC Detection Condition
Trouble Area
C1A4A
While power switch is on (IG), skid control buzzer circuit malfunction signal is received by brake booster with master cylinder (skid control ECU) for 1 second
  1. Electronically controlled brake system
  2. Driving support ECU

WIRING DIAGRAM


E187972E05


INSPECTION PROCEDURE

1.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SKID CONTROL BUZZER)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the intelligent tester on.

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

  1. Perform the Active Test.

    OK:
    Skid control buzzer sounds.



NG
GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM (Click here)
OK


2.CHECK WHETHER DTC OUTPUT RECURS (DTC C1A4A)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Clear the DTCs (Click here).

  1. Perform the following to make sure that the DTC detection conditions are met.

    HINT:
    If the detection conditions are not met, the malfunction cannot be detected.

    1. Drive the vehicle at a speed of 40 km/h (25 mph) or more.

    2. Turn the cruise control main switch on.

    3. Push the -SET switch to activate the cruise control.

  1. Enter the following menus: Powertrain / Radar Cruise / DTC.

  1. Read the DTCs.

    Result:
    Result
    		Proceed to
    DTC is not output
    		A
    DTC C1A4A is output
    		B



B
Go to step 3
A

USE SIMULATION METHOD TO CHECK (Click here)  

3.REPLACE DRIVING SUPPORT ECU

  1. Replace the driving support ECU (Click here).


NEXT


4.CHECK WHETHER DTC OUTPUT RECURS (DTC C1A4A)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Clear the DTCs (Click here).

  1. Perform the following to make sure that the DTC detection conditions are met.

    HINT:
    If the detection conditions are not met, the malfunction cannot be detected.

    1. Drive the vehicle at a speed of 40 km/h (25 mph) or more.

    2. Turn the cruise control main switch on.

    3. Push the -SET switch to activate the cruise control.

  1. Enter the following menus: Powertrain / Radar Cruise / DTC.

  1. Read the DTCs.

    Result:
    Result
    		Proceed to
    DTC is not output
    		A
    DTC C1A4A is output
    		B



B
Go to step 5
A

END 

5.REPLACE BRAKE BOOSTER WITH MASTER CYLINDER

  1. Replace the brake booster with master cylinder (skid control ECU) (Click here for LHD, Click here for RHD).


NEXT


6.CHECK WHETHER DTC OUTPUT RECURS (DTC C1A4A)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Clear the DTCs (Click here).

  1. Perform the following to make sure that the DTC detection conditions are met.

    HINT:
    If the detection conditions are not met, the malfunction cannot be detected.

    1. Drive the vehicle at a speed of 40 km/h (25 mph) or more.

    2. Turn the cruise control main switch on.

    3. Push the -SET switch to activate the cruise control.

  1. Enter the following menus: Powertrain / Radar Cruise / DTC.

  1. Read the DTCs.

    Result:
    Result
    		Proceed to
    DTC is not output
    		A
    DTC C1A4A is output
    		B



B
REPLACE POWER MANAGEMENT CONTROL ECU (Click here)
A

END