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 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 CSEL 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

A01T9X9E08

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 detected within 10 seconds after the engine switch is turned off from ON.

  • 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 systems are functioning properly.

    Click here

PROCEDURE


  1. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    1. A01TDC8C05
      *a

      Front view of wire harness connector

      (to Door control receiver)

      Disconnect the L35 door control receiver connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      L35-4 (+5) - L35-1 (GND) Engine switch off, all doors closed and electrical key transmitter sub-assembly switch not pressed → electrical key transmitter sub-assembly switch pressed Below 1 V → 4.5 to 5.5 V
      L35-2 (CSEL) - L35-1 (GND) Engine switch off and all doors closed Below 1 V → 4.5 to 6.0 V → Below 1 V
      L35-5 (DATA) - L35-1 (GND) All doors closed, all doors locked and electrical key transmitter sub-assembly switch not pressed → electrical key transmitter sub-assembly switch pressed Below 1 V → 10 to 16 V → Below 1 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      L35-1 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE DOOR CONTROL RECEIVER for Sedan: Click here
    REPLACE DOOR CONTROL RECEIVER for Hatchback: Click here
    REPLACE DOOR CONTROL RECEIVER for Wagon: Click here

    NG

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


    1. Disconnect the E34 and E33 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
      E34-6 (CSEL) - L35-2 (CSEL) Always Below 1 Ω
      E34-17 (RDAM) - L35-5 (DATA) Always Below 1 Ω
      E34-5 (RCO) - L35-4 (+5) Always Below 1 Ω
      E33-11 (E) - Body ground Always Below 1 Ω
      E34-6 (CSEL) - Body ground Always 10 kΩ or higher
      L35-2 (CSEL) - Body ground Always 10 kΩ or higher
      E34-17 (RDAM) - Body ground Always 10 kΩ or higher
      L35-5 (DATA) - Body ground Always 10 kΩ or higher
      E34-5 (RCO) - Body ground Always 10 kΩ or higher
      L35-4 (+5) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR