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 related 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 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

  • Certification ECU (smart key ECU assembly)

WIRING DIAGRAM


  1. for 12 Pin Type

    B003YLME78

  2. for 5 Pin Type

    A0021MLE81

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 power switch being turned from on (IG) to off.

  • 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 (Click here) after registration Click here of the transmitter IDs into the door control receiver if the door control receiver has been replaced.*


  • *: w/ Tire Pressure Warning System

PROCEDURE


  1. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    1. Disconnect the Q37*1 or Q38*2 door control receiver connector.


      • *1: for 5 Pin Type

      • *2: for 12 Pin Type

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

      A0021WEC14
      *a

      Component with harness connected

      (Certification ECU (Smart Key ECU Assembly))

      		 - -
      Standard Voltage
      Tester Connection Condition Specified Condition
      K136-20 (RDAM) - K137-11 (E) always 11 to 14 V
      K136-18 (RCO) - K137-11 (E) always Below 1 V → 4.5 to 5.5 V pulse generation at regular intervals
      Standard Resistance
      Tester Connection Condition Specified Condition
      K137-11 (E) - Body ground Always Below 1 Ω
      Result
      Result Proceed to
      NG A
      OK (for 5 Pin Type) B
      OK (for 12 Pin Type) C

    B

    REPLACE DOOR CONTROL RECEIVER Click here

    C

    REPLACE DOOR CONTROL AND TIRE PRESSURE MONITORING SYSTEM RECEIVER ASSEMBLY Click here

    A

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


    1. Disconnect the K136 certification ECU (smart key ECU assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K136-20 (RDAM) - Q37-5 (DATA)*1 Always Below 1 Ω
      K136-20 (RDAM) - Q38-9 (DATA)*2
      K136-18 (RCO) - Q37-4 (+5)*1 Always Below 1 Ω
      K136-18 (RCO) - Q38-10 (+5)*2
      Q37-1 (GND) - Body ground*1 Always Below 1 Ω
      Q38-12 (GND) - Body ground*2
      Q37-5 (DATA) or K136-20 (RDAM) - Body ground*1 Always 10 kΩ or higher
      Q38-9 (DATA) or K136-20 (RDAM) - Body ground*2
      Q37-4 (+5) or K136-18 (RCO) - Body ground*1 Always 10 kΩ or higher
      Q38-10 (+5) or K136-18 (RCO) - Body ground*2

      • *1: for 5 Pin Type

      • *2: for 12 Pin Type

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR