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 smart door control receiver assembly 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 smart door control receiver assembly. The smart door control receiver assembly 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 smart door control receiver assembly.

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

  • Wire harness or connector

  • Smart door control receiver assembly

  • Certification ECU (smart key ECU assembly)

WIRING DIAGRAM

A002A9JE64

CAUTION / NOTICE / HINT

Note


  • When replacing or inspecting the smart door control receiver assembly and wire harness, do not change the position or length of the wire harness. If the wire harness is too close to the smart door control receiver assembly, entry and wireless function performance may be affected.

  • This DTC is not stored within 10 seconds of the engine switch being turned from on (IG) to off.

  • 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 system is functioning properly.

    Click here

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

    Click here

PROCEDURE


  1. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    1. Disconnect the M27 smart door control receiver assembly connector.

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

      A0027GLC09
      *a

      Component with harness connected

      (Certification ECU (Smart Key ECU Assembly))

      		 - -
      Standard Voltage
      Tester Connection Condition Specified Condition
      F12-20 (RDAM) - F13-11 (E) always 11 to 14 V
      F12-18 (RCO) - F13-11 (E) always Below 1 V → 4.5 to 5.5 V pulse generation at regular intervals
      Standard Resistance
      Tester Connection Condition Specified Condition
      F13-11 (E) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE SMART DOOR CONTROL RECEIVER ASSEMBLY Click here

    NG

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


    1. Disconnect the F12 certification ECU (smart key ECU assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F12-20 (RDAM) - M27-5 (DATA) Always Below 1 Ω
      F12-18 (RCO) - M27-4 (+5) Always Below 1 Ω
      M27-1 (GND) - Body ground Always Below 1 Ω
      M27-5 (DATA) or F12-20 (RDAM) - Body ground Always 10 kΩ or higher
      M27-4 (+5) or F12-18 (RCO) - 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