Toyota Avalon Service & Repair Manual: Stop Light Relay Circuit (C1A4B)

Toyota Avalon Service & Repair Manual / Vehicle Interior / Pre-collision / Pre-collision System(for Gasoline Model) / Stop Light Relay Circuit (C1A4B)

DESCRIPTION

The skid control ECU (brake actuator assembly) sends a stop light operation request signal to the stop light relay (stop light switch assembly). If the skid control ECU (brake actuator assembly) detects a malfunction in the stop light relay (stop light switch assembly) circuit, the driving support ECU assembly stores DTC C1A4B.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1A4B

Stop Light Relay Circuit

Both of the following conditions are met:

  • All of the following conditions are met:
    • 3 seconds have elapsed since the engine switch was turned to on (IG).
    • The battery voltage is 10 V or more for 3 seconds or more.
  • All of the following conditions are met for 1 second or more:
    • Communication between the driving support ECU assembly and skid control ECU (brake actuator assembly) is normal.
    • The driving support ECU assembly receives a stop light relay circuit malfunction signal from the skid control ECU (brake actuator assembly).

Electronically controlled brake system

CAUTION / NOTICE / HINT

NOTICE:

The pre-collision system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

Click here

PROCEDURE

1.

GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM

HINT:

If DTC C1A4B is output by the pre-collision system, perform troubleshooting for the electronically controlled brake system.

Click here

NEXT

END
    Vehicle Information Not Obtained (C1A02)

    Front Radar Sensor (C1A10)

    See More:

    Toyota Avalon Service & Repair Manual > Can Communication System(for Gasoline Model): Check Bus 2 Line for Short to GND
    DESCRIPTION There may be a short circuit between one of the CAN bus lines and GND when there is no resistance between terminal 18 (CA4H) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3, or terminal 17 (CA4L) of the central gateway ECU (network gateway ECU) and termin ...

    Toyota Avalon Owners Manual

    Toyota Avalon Service & Repair Manual

    © 2023 Copyright www.tavalon.net
    0.0989