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

DTC Code DTC Name
B1242 Wireless Door Lock Tuner Circuit Malfunction

DESCRIPTION

The door control receiver receives signals from the transmitter and sends these signals to the main body ECU. This DTC is stored when the applicable RDA signal cannot be received within 1 second of the PRG signal being output from the main body ECU.

DTC Code

DTC Detection Condition

Trouble Area

B1242

The applicable RDA signal cannot be received within 1 second of the PRG signal being output from the main body ECU.

  • Harness or connector

  • Door control receiver

  • Main body ECU

WIRING DIAGRAM

U123676E02

CAUTION / NOTICE / HINT

Note:

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

  • As the door control battery is installed between the vehicle battery and main body ECU (instrument panel junction block assembly), first perform the inspections in On-Vehicle Inspection to confirm that there are no malfunctions in the power source circuit for the main body ECU (instrument panel junction block assembly) before performing this troubleshooting procedure (Click here).

PROCEDURE

  1. CLEAR DTC

    1. Clear the DTCs (Click here).

  2. CHECK FOR DTC

    1. Check for DTCs (Click here).

      OK

      DTC B1242 is not output.

    USE SIMULATION METHOD TO CHECK

    (Click here)

  3. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - DOOR CONTROL RECEIVER)

    1. U122441E02

      Disconnect the H81 ECU connector.

    2. Disconnect the O14 receiver connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H81-5 (RDA) - O14-2 (RDA)

      Always

      Below 1 Ω

      H81-6 (PRG) - O14-3 (PRG)

      H81-5 (RDA) or O14-2 (RDA) - Body ground

      Always

      10 kΩ or higher

      H81-6 (PRG) or O14-3 (PRG) - Body ground
      Table 1. Text in Illustration

      *1

      Front view of wire harness connector

      (to Main Body ECU)

      *2

      Front view of wire harness connector

      (to Door Control Receiver)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  4. CHECK HARNESS AND CONNECTOR (DOOR CONTROL RECEIVER - BATTERY AND BODY GROUND)

    1. U122440E02

      Disconnect the O14 receiver connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      O14-1 (GND) - Body ground

      Always

      Below 1 Ω

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      O14-5 (+B) - Body ground

      Always

      11 to 14 V
      Table 2. Text in Illustration

      *1

      Front view of wire harness connector

      (to Door Control Receiver)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  5. REPLACE DOOR CONTROL RECEIVER

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

    2. Perform the registration procedures (Click here).

  6. CLEAR DTC

    1. Clear the DTCs (Click here).

  7. CHECK FOR DTC

    1. Check for DTCs (Click here).

      OK

      DTC B1242 is not output.

    END (DOOR CONTROL RECEIVER IS DEFECTIVE)

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)