DYNAMIC RADAR CRUISE CONTROL SYSTEM, Diagnostic DTC:C1A05

DTC Code DTC Name
C1A05 Stop Light Switch Circuit

DESCRIPTION

When the brake pedal is depressed, the stop light switch assembly sends a brake pedal operation signal to the driving support ECU assembly. After reception of this signal, the driving support ECU assembly cancels the dynamic radar cruise control system. When the driving support ECU assembly detects a problem in the stop light switch assembly circuit, DTC C1A05 is stored.

DTC No. DTC Detection Condition Trouble Area
C1A05 When the power switch is on (IG) or the cruise control main switch (ON-OFF button) is on, the driving support ECU assembly detects a malfunction in the signal received from the stop light switch assembly.

  • Stop light switch assembly

  • Driving support ECU assembly

  • Harness or connector

WIRING DIAGRAM

A003XBGE01

INSPECTION PROCEDURE

Tech Tips

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY POWER SOURCE)


    1. A003VAUE75
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Stop Light Switch Assembly)

      Disconnect the A25 stop light switch assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A25-2 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY POWER SOURCE)


    1. A003VAUE75
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Stop Light Switch Assembly)

      Disconnect the A25 stop light switch assembly connector.

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A25-4 - Body ground Power switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Remove the stop light switch assembly Click here.

    2. Inspect the stop light switch assembly Click here.


    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - DRIVING SUPPORT ECU ASSEMBLY)


    1. Disconnect the A25 stop light switch assembly connector.

    2. Disconnect the H5 driving support ECU assembly connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A25-3 - H5-28 (ST1-) Always Below 1 Ω
      A25-1 - H5-27 (STP-) Always Below 1 Ω
      A25-3 or H5-28 (ST1-) - Body ground Always 10 kΩ or higher
      A25-1 or H5-27 (STP-) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here