WIRELESS DOOR LOCK CONTROL SYSTEM (w/ Smart Entry and Start System), Diagnostic DTC:B1242

DTC Code DTC Name
B1242 Wireless Door Lock Tuner Circuit Malfunction

DESCRIPTION

The door control receiver is used to receive electrical waves relating to the entry functions of the smart entry and start system. The certification ECU (smart key ECU assembly) decodes the requested smart entry and start system 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 (driver side junction block assembly) 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 (driver side junction block assembly)).

DTC No. DTC Detection Condition Trouble Area
B1242

  • 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.

  • Wire harness or connector

  • Door control receiver

  • Certification ECU (Smart key ECU assembly)

WIRING DIAGRAM

A01EMO3E01

INSPECTION PROCEDURE

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.

PROCEDURE


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


    1. A01EK91E01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Certification ECU (Smart Key ECU Assembly))
      *2

      Front view of wire harness connector

      (to Door Control Receiver)

      Disconnect the D25 and D26 certification ECU (smart key ECU assembly) connectors.

    2. Disconnect the M16 door control receiver connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D26-16 (RSSI) - M16-2 (RSSI) Always Below 1 Ω
      D26-15 (RDA) - M16-5 (DATA) Always Below 1 Ω
      D26-5 (RCO) - M16-4 (+5) Always Below 1 Ω
      D25-15 (E) - Body ground Always Below 1 Ω
      M16-1 (GND) - Body ground Always Below 1 Ω
      D26-16 (RSSI) or M16-2 (RSSI) - Body ground Always 10 kΩ or higher
      D26-15 (RDA) or M16-5 (DATA) - Body ground Always 10 kΩ or higher
      D26-5 (RCO) or M16-4 (+5) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    1. A01ELPLE06
      Text in Illustration
      *1

      Component with harness connected

      (Certification ECU (Smart Key ECU Assembly))

      Reconnect the D25 and D26 certification ECU (smart key ECU assembly) connectors.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      D26-5 (RCO) - D25-15 (E) Engine switch off, all doors closed and transmitter switch pressed 4.5 to 5.5 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 DTCs.

      OK
      DTC B1242 is not output.

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

    END (DOOR CONTROL RECEIVER WAS DEFECTIVE)