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 engine switch is on (IG) and the dynamic radar cruise control system is turned on using the cruise control main switch (ON/OFF button), the driving support ECU assembly detects a malfunction in the signal from the stop light switch assembly circuit.

  • Stop light switch assembly

  • Harness or connector

  • Driving support ECU assembly

WIRING DIAGRAM

B003TW7E02

CAUTION / NOTICE / HINT

Note


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

  • When replacing the driving support ECU assembly, make sure to replace it with a new one. If a device 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, and as a result, a DTC may be stored.

PROCEDURE


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


    1. B003TSQC08
      *a

      Front view of wire harness connector

      (to Stop Light Switch Assembly)

      Disconnect the A56 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
      A56-1 (B) - Body ground Always 11 to 14 V
      A56-5 (B) - Body ground Engine switch on (IG) 11 to 14 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      A56-3 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the M2 driving support ECU assembly connector.

    2. Disconnect the A56 stop light switch assembly connector.

    3. Disconnect the A13 certification ECU (smart key ECU assembly) connector.

    4. Disconnect the A105 brake actuator assembly (skid control ECU) connector.

    5. Disconnect the K46 transmission floor shift assembly (shift lock control unit) connector.

    6. Disconnect the 2D stop light relay (semiconductor power integration ECU) connector.

    7. for 2GR-FKS:


      1. Disconnect the A108 ECM connector.

    8. for 8AR-FTS:


      1. Disconnect the A91 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      M2-15 (STP-) - A56-2 (L) Always Below 1 Ω
      M2-1 (ST1-) - A56-4 (L) Always Below 1 Ω
      M2-15 (STP-) or A56-2 (L) - Body ground Always 10 kΩ or higher
      M2-1 (ST1-) or A56-4 (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. Check for DTCs.

      Click here


      Powertrain > Radar Cruise > Trouble Codes
      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