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 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. Detection Item DTC Detection Condition Trouble Area
C1A05 Stop Light Switch Circuit When the power switch is on (IG) and the cruise control switch is on, the driving support ECU assembly detects a malfunction in the signal from stop light switch assembly circuit for 2 seconds or more.

  • Stop light switch assembly

  • Harness or connector

  • Driving support ECU assembly

WIRING DIAGRAM

A01WYP9E48

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK TERMINAL VOLTAGE (POWER SOURCE OF STOP LIGHT SWITCH ASSEMBLY)


    1. B004FUQC47
      *a

      Front view of wire harness connector

      (to Stop Light Switch Assembly)

      Disconnect the A52 stop light switch assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A52-1 (B) - A52-3 (GND) Power switch off 11 to 14 V
      A52-5 (B) - A52-3 (GND) Power switch on (IG) 11 to 14 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      A52-3 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - AUXILIARY BATTERY AND BODY GROUND)

    OK

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


    1. Disconnect the Q1 driving support ECU assembly connector.

    2. Disconnect the A52 stop light switch assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q1-27 (STP-) - A52-2 (L) Always Below 1 Ω
      Q1-28 (ST1-) - A52-4 (L) Always Below 1 Ω
      Q1-27 (STP-) or A52-2 (L) - Body ground Always 10 kΩ or higher
      Q1-28 (ST1-) or A52-4 (L) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. REPLACE STOP LIGHT SWITCH ASSEMBLY


    1. Replace the stop light switch assembly.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  4. CHECK FOR DTCs (RADAR CRUISE)


    1. Clear the DTCs.

      Click here


      Powertrain > Radar Cruise > Clear DTCs

    2. Make sure that the DTC detection conditions are met.

      Tech Tips

      If the detection conditions are not met, the system cannot detect the malfunction.

    3. Check for DTCs.

      Click here


      Powertrain > Radar Cruise > Trouble Codes

      Note

      When replacing the driving support ECU assembly, always replace it with a new one. If a driving support ECU assembly which was installed to another vehicle is used, the information stored in the driving support ECU assembly will not match the information from the vehicle. As a result, a DTC may be stored.

      Result
      Result Proceed to
      DTC C1A05 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