PRE-CRASH SAFETY SYSTEM, Diagnostic DTC:C1A4B

DTC Code DTC Name
C1A4B Stop Light Relay Circuit

DESCRIPTION

The stop light switch outputs a brake pedal operation signal to the driving support ECU.

DTC No. DTC Detection Condition Trouble Area
C1A4B When the ignition switch is ON, a stop light relay malfunction signal is received from the skid control ECU.

  • Vehicle stability control system

  • CAN communication system

  • Brake actuator assembly (Skid control ECU)

  • Driving support ECU

INSPECTION PROCEDURE

Note

When this DTC is output, malfunction in the lighting system is suspected. Check if the lighting system is functioning normally Click here.

PROCEDURE


  1. CHECK FOR DTC (VEHICLE STABILITY CONTROL SYSTEM)


    1. Check for DTCs Click here.

      OK
      Vehicle stability control system DTCs are not output.

    NG

    GO TO VEHICLE STABILITY CONTROL SYSTEM Click here

    OK

  2. REPLACE BRAKE ACTUATOR ASSEMBLY


    1. Replace the skid control ECU Click here.


    NEXT

  3. CHECK FOR DTC


    1. Check for DTCs. Click here.

      OK
      DTC U0122 is not output.

    NG

    GO TO CAN COMMUNICATION SYSTEM Click here

    OK

    END (BRAKE ACTUATOR ASSEMBLY [SKID CONTROL ECU] IS DEFECTIVE)