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 radar cruise control system. When the driving support ECU assembly detects a malfunction in the stop light switch circuit, DTC C1A05 is stored.

DTC No. DTC Detection Condition Trouble Area
C1A05 Voltages of terminals ST1- and STP- of driving support ECU assembly are both below 1 V for 1 second

  • Stop light switch assembly

  • Stop light switch circuit

  • Driving support ECU assembly

WIRING DIAGRAM

A005D58E62

CAUTION / NOTICE / HINT

Note

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. A005DZ7E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Stop Light Switch Assembly)

      Disconnect the 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
      A79-6 (B) - Body ground Power switch on (IG) 11 to 14 V
      A79-7 (B) - Body ground Always 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A79-2 (GND) - Body ground Always Below 1 Ω

    4. Reconnect the stop light switch assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the stop light switch assembly connector.

    2. Disconnect the driving support ECU assembly connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A79-3 (L) - L60-27 (STP-) Always Below 1 Ω
      A79-5 (L) - L60-28 (ST1-) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A79-3 (L) or L60-27 (STP-) - Body ground Always 10 kΩ or higher
      A79-5 (L) or L60-28 (ST1-) - Body ground Always 10 kΩ or higher

    4. Reconnect the stop light switch assembly connector.

    5. Reconnect the driving support ECU assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. REPLACE STOP LIGHT SWITCH ASSEMBLY


    1. Replace the stop light switch assembly Click here.


    NEXT

  4. CHECK FOR DTCs (C1A05)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Clear the DTCs Click here.

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

      Tech Tips

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


      1. Drive the vehicle at a speed of between 50 km/h (30 mph) and 170 km/h (105 mph).

      2. Turn the cruise control system on using the cruise control switch (ON-OFF button).

      3. Push the cruise control switch to -/SET to begin control of vehicle speed using the cruise control system.

    5. Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.

    6. Check for DTCs.

      Result
      Result Proceed to
      DTC is not output A
      DTC C1A05 is output B

    A

    END (STOP LIGHT SWITCH ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here