WIRELESS DOOR LOCK CONTROL SYSTEM, Diagnostic DTC:B1242

DTC Code DTC Name
B1242 Wireless Door Lock Tuner Circuit Malfunction

DESCRIPTION

The door control receiver is used to receive radio waves relating to the entry functions of the electrical key transmitter sub-assembly. The certification ECU (smart key ECU assembly) decodes the requested electrical key transmitter sub-assembly operation by identifying a key code based on the radio waves received via the door control receiver. The door control receiver receives a signal from the electrical key transmitter sub-assembly and sends signals to the main body ECU (multiplex network body ECU) through the certification ECU (smart key ECU assembly). (ex. if a door lock operation is requested, the certification ECU (smart key ECU assembly) sends a door lock command to the main body ECU (multiplex network body ECU)).

DTC No. Detection Item DTC Detection Condition Trouble Area
B1242 Wireless Door Lock Tuner Circuit Malfunction

  • Short in RDAM to ground between the certification ECU (smart key ECU assembly) and the door control receiver.

  • Short in RDAM to ground when RCO (5 V) output from the ECU is off.

  • Wire harness or connector

  • Door control receiver

  • No. 1 amplifier antenna assembly

  • Certification ECU (smart key ECU assembly)

WIRING DIAGRAM

B002DRCE03
B002DRCE02

CAUTION / NOTICE / HINT

Note


  • When replacing or inspecting the door control receiver and wire harness, do not change the position or length of the wire harness. If the wire harness is too close to the door control receiver, entry and wireless function performance may be affected.

  • This DTC is not stored within 10 seconds of the engine switch being turned from on (IG) to off.

  • Before replacing the certification ECU (smart key ECU assembly) or electrical key transmitter sub-assembly, refer to Service Bulletin.

  • The wireless door lock control system uses the CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting.

    Troubleshoot the wireless door lock control system after confirming that the communication system is functioning properly.

    Click here

  • When replacing the door control receiver, read the transmitter IDs (tire pressure warning system) stored in the old ECU using the GTS and write them down before removal.*

    Click here

  • It is necessary to perform initialization after registration of the transmitter IDs into the door control receiver if the door control receiver has been replaced.*

    Click here

    Click here


PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs.

      Click here

      OK
      DTC B1242 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  3. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    1. for LHD


      1. B002CHGC08
        *a

        Component with harness connected

        (Certification ECU (Smart Key ECU Assembly))

        Disconnect the T27*1 or T26*2 door control receiver connector.

        *1: w/ Tire Pressure Warning System

        *2: w/o Tire Pressure Warning System

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        A21-11 (E) - Body ground Always Below 1 Ω

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

        Tester Connection Condition Specified Condition
        T1-5 (RCO) - A21-11 (E) Always Below 1 V → 4.5 to 5.5 V (Pulse generation)
        T1-17 (RDAM) - A21-11(E) Always 11 to 14 V

    2. for RHD


      1. B002CHGC09
        *a

        Component with harness connected

        (Certification ECU (Smart Key ECU Assembly))

        Disconnect the T27*1 or T26*2 door control receiver connector.

        *1: w/ Tire Pressure Warning System

        *2: w/o Tire Pressure Warning System

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        A21-11 (E) - Body ground Always Below 1 Ω

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

        Tester Connection Condition Specified Condition
        U1-5 (RCO) - A21-11 (E) Always Below 1 V → 4.5 to 5.5 V (Pulse generation)
        U1-17 (RDAM) - A21-11(E) Always 11 to 14 V
      Result
      Result Proceed to
      OK A
      NG (w/ Tire Pressure Warning System) B
      NG (w/o Tire Pressure Warning System) C

    B

    REPLACE ELECTRICAL KEY AND TPMS RECEIVER ASSEMBLY Click here

    C

    REPLACE SMART DOOR CONTROL RECEIVER ASSEMBLY Click here

    A

  4. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - DOOR CONTROL RECEIVER)


    1. for LHD


      1. Disconnect the T1 certification ECU (smart key ECU assembly) connector.

      2. Disconnect the T27*1 or T26*2 door control receiver connector.

        *1: w/ Tire Pressure Warning System

        *2: w/o Tire Pressure Warning System

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

        Standard Resistance
        w/ Tire Pressure Warning System
        Tester Connection Condition Specified Condition
        T1-5 (RCO) - T27-10 (+5) Always Below 1 Ω
        T1-17 (RDAM) - T27-9 (DATA) Always Below 1 Ω
        T1-5 (RCO) or T27-10 (+5) - Body ground Always 10 kΩ or higher
        T1-17 (RDAM) or T27-9 (DATA) - Body ground Always 10 kΩ or higher
        w/o Tire Pressure Warning System
        Tester Connection Condition Specified Condition
        T1-5 (RCO) - T26-2 (+5) Always Below 1 Ω
        T1-17 (RDAM) - T26-3 (DATA) Always Below 1 Ω
        T1-5 (RCO) or T26-2 (+5) - Body ground Always 10 kΩ or higher
        T1-17 (RDAM) or T26-3 (DATA) - Body ground Always 10 kΩ or higher

    2. for RHD


      1. Disconnect the U1 certification ECU (smart key ECU assembly) connector.

      2. Disconnect the T27*1 or T26*2 door control receiver connector.

        *1: w/ Tire Pressure Warning System

        *2: w/o Tire Pressure Warning System

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

        Standard Resistance
        w/ Tire Pressure Warning System
        Tester Connection Condition Specified Condition
        U1-5 (RCO) - T27-10 (+5) Always Below 1 Ω
        U1-17 (RDAM) - T27-9 (DATA) Always Below 1 Ω
        U1-5 (RCO) or T27-10 (+5) - Body ground Always 10 kΩ or higher
        U1-17 (RDAM) or T27-9 (DATA) - Body ground Always 10 kΩ or higher
        w/o Tire Pressure Warning System
        Tester Connection Condition Specified Condition
        U1-5 (RCO) - T26-2 (+5) Always Below 1 Ω
        U1-17 (RDAM) - T26-3 (DATA) Always Below 1 Ω
        U1-5 (RCO) or T26-2 (+5) - Body ground Always 10 kΩ or higher
        U1-17 (RDAM) or T26-3 (DATA) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (DOOR CONTROL RECEIVER - NO. 1 AMPLIFIER ANTENNA ASSEMBLY)


    1. Disconnect the T42*1 or T26*2 door control receiver connector.

      *1: w/ Tire Pressure Warning System

      *2: w/o Tire Pressure Warning System

    2. Disconnect the T43*1 or T44*2 No. 1 amplifier antenna assembly connector.

      *1: w/ Tire Pressure Warning System

      *2: w/o Tire Pressure Warning System

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

      Standard Resistance
      w/ Tire Pressure Warning System
      Tester Connection Condition Specified Condition
      T42-1 - T43-1 Always Below 1 Ω
      T42-1 or T43-1 - Body ground Always 10 kΩ or higher
      w/o Tire Pressure Warning System
      Tester Connection Condition Specified Condition
      T26-7 - T44-1 Always Below 1 Ω
      T26-7 or T44-1 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. REPLACE NO.1 AMPLIFIER ANTENNA ASSEMBLY


    1. Temporarily replacing the No. 1 amplifier antenna assembly with a new or normally functioning one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  7. CLEAR DTC


    1. Clear the DTCs.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  8. CHECK FOR DTC


    1. Check for DTCs.

      Click here

      OK
      DTC B1242 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (NO. 1 AMPLIFIER ANTENNA ASSEMBLY IS DEFECTIVE)

    NG

  9. REPLACE DOOR CONTROL RECEIVER


    1. Temporarily replacing the door control receiver with a new or normally functioning one.


      Result
      Proceed to
      NEXT

    NEXT

  10. CLEAR DTC


    1. Clear the DTCs.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  11. CHECK FOR DTC


    1. Check for DTCs.

      Click here

      OK
      DTC B1242 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (DOOR CONTROL RECEIVER IS DEFECTIVE)

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)