WIRELESS DOOR LOCK CONTROL SYSTEM, Diagnostic DTC:B1242

DTC Code DTC Name
B1242 Wireless Door Lock Tuner Circuit Malfunction

DESCRIPTION

The door lock receiver is used to receive electrical waves relating to the entry functions of the entry and start system (for Entry Function). The certification ECU (smart key ECU assembly) decodes the requested entry and start system (for Entry Function) operation by identifying a key code based on the electric waves received via the door control receiver. The door control receiver receives a signal from the door control transmitter and sends signals to the main body ECU through the certification ECU (smart key ECU assembly). The certification ECU (smart key ECU assembly) then sends a command, according to the requested operation, to each ECU (ex. if door lock operation is requested, the certification ECU (smart key ECU assembly) sends a door lock command to the main body ECU).

This DTC is stored when one of the following occurs: 1) a short in RDA or RSSI to ground between the certification ECU (smart key ECU assembly) and the door control receiver, or 2) a short in RDA or RSSI to ground when RCO (5 V) output from the ECU is off.

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.

  • Before performing the inspection, check that there are no problems related to the CAN communication system and LIN communication system.

  • When using the intelligent tester with the engine switch off to troubleshoot: Connect the intelligent tester to the vehicle, and turn the front door courtesy light switch LH on and off at 1.5 second intervals until communication between the intelligent tester and vehicle begins.

DTC Code DTC Detection Condition Trouble Area
B1242

One of the following conditions is met:


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

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

  • Harness or connector

  • Door control receiver

  • Certification ECU (smart key ECU assembly)

WIRING DIAGRAM

A01EQWBE02

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - DOOR CONTROL RECEIVER)


    1. A01ENAAE01

      Disconnect the E29 ECU connector.

    2. Disconnect the L21 receiver connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E29-39 (RSSI) - L21-2 (RSSI) Always Below 1 Ω
      E29-38 (RDA) - L21-5 (DATA)
      E29-29 (RCO) - L21-4 (+5)
      L21-1 (GND) - Body ground
      E29-39 (RSSI) or L21-2 (RSSI) - Body ground Always 10 kΩ or higher
      E29-38 (RDA) or L21-5 (DATA) - Body ground
      E29-29 (RCO) or L21-4 (+5) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    1. A01EP9UE01

      Disconnect the L21 receiver connector.

    2. Reconnect the E29 ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      L21-4 (+5) - Body ground Always 4.5 to 5.4 V

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

  3. REPLACE DOOR CONTROL RECEIVER


    1. Temporarily replace the door control receiver with a new one Click here.


    NEXT

  4. CHECK FOR DTC


    1. Clear the DTC Click here.

    2. Recheck for DTC Click here.

      OK
      DTC B1242 is not output.

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

    END (DOOR CONTROL RECEIVER IS DEFECTIVE)