WIRELESS DOOR LOCK CONTROL SYSTEM(w/ 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 entry and start system. The certification ECU (smart key ECU assembly) decodes the requested 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 electrical key transmitter sub-assembly 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).

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 RC0 (12 V) output from the ECU is off.

  • Door control receiver

  • Wire harness or connector

  • Certification ECU (Smart Key ECU Assembly)

WIRING DIAGRAM

A004J1BE71
*a DATA
*b Certification ECU (Smart Key ECU Assembly)
*c Door Control Receiver

CAUTION / NOTICE / HINT

Note


  • The entry and start system uses multiplex communication. First perform the inspections in "How to Proceed with Troubleshooting" to confirm that there are no communication malfunctions before proceeding with troubleshooting (See page ).

    Click here

  • Before replacing the certification ECU (smart key ECU assembly), refer to the entry and start system (for Entry Function) Click here.

  • 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.

PROCEDURE


  1. INSPECT CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    A004HC2E01
    Text in Illustration
    *a

    Front view of wire harness connector

    (to Door Control Receiver)

    1. Disconnect the H26 door control receiver connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H26-1 (GND) - Body ground Always Below 1 Ω
      Standard Voltage
      Tester Connection Condition Specified Condition
      H26-4 (+5) - H26-1 (GND) Always Below 1 V → 4.5 to 5.5 V (Pulse generation)
      H26-2 (RSSI) - H26-1 (GND) Always 11 to 14 V
      H26-5 (DATA) - H26-1 (GND) Always 11 to 14 V
      Result
      Result Proceed to
      NG A
      OK B

    B

    REPLACE DOOR CONTROL RECEIVER Click here

    A

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


    1. Disconnect the D40 and D48 certification ECU (smart key ECU assembly) connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D40-19 (RSSI) - H26-2 (RSSI) Always Below 1 Ω
      D40-17 (RDA) - H26-5 (DATA) Always Below 1 Ω
      D40-5 (RCO) - H26-4 (+5) Always Below 1 Ω
      D48-11 (GND) - Body ground Always Below 1 Ω

    OK

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR