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WIRELESS DOOR LOCK CONTROL SYSTEM, Diagnostic DTC:B1242

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DTC Code DTC Name
B1242 Wireless Door Lock Tuner Circuit Malfunction
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DESCRIPTION

The door control receiver is used to receive radio waves relating 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 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). 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 (multiplex network body ECU)).

DTC No. DTC Detection Condition Trouble Area
B1242

  • Short in RDAM or CSEL to ground between the certification ECU (smart key ECU assembly) and the 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)
A0003F7C08
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WIRING DIAGRAM

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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, smart and wireless function performance may be affected.

  • Before performing the inspection, check that there are no problems related to the CAN communication system (Click here).

  • When replacing the door control receiver, read the transmitter IDs (tire pressure warning system) stored in the old ECU using the GTS and write them down before removal (Click here).*

  • It is necessary to perform initialization (See page ) after registration (Click here) of the transmitter IDs into the door control receiver if the door control receiver has been replaced.*

  • This DTC is not detected within 10 seconds after the power switch turned to off from on (IG).


  • *: for China and Taiwan

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PROCEDURE


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    CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    1. A0008Z9C18
      *a

      Component with harness connected

      (Certification ECU (Smart Key ECU Assembly))

      		 - -

      Disconnect the P29 or P30 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
      Q37-5 (RCO) - A72-11 (E) Always

      Below 1 V → 4.5 to 5.5 V

      (Pulse generation)
      Q37-17 (RDAM) - A72-11 (E) Always 11 to 14 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      A72-11 (E) - Body ground Always Below 1 Ω
      Result
      Result Proceed to
      NG A
      OK (for China, Taiwan and Hong Kong) B
      OK (except China, Taiwan and Hong Kong) C

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


    1. Disconnect the A72 and Q37 certification ECU (smart key ECU assembly) connectors.

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

      Standard Resistance
      Table 1. Door Control Receiver with 12 Pin Connector
      Tester Connection Condition Specified Condition
      Q37-17 (RDAM) - P29-9 (DATA) Always Below 1 Ω
      Q37-5 (RCO) - P29-10 (+5) Always Below 1 Ω
      P29-12 (GND) - Body ground Always Below 1 Ω
      Q37-17 (RDAM) or P29-9 (DATA) - Body ground Always 10 kΩ or higher
      Q37-5 (RCO) or P29-10 (+5) - Body ground Always 10 kΩ or higher
      Standard Resistance
      Table 2. Door Control Receiver with 5 Pin Connector
      Tester Connection Condition Specified Condition
      Q37-17 (RDAM) - P30-5 (DATA) Always Below 1 Ω
      Q37-5 (RCO) - P30-4 (+5) Always Below 1 Ω
      P30-1 (GND) - Body ground Always Below 1 Ω
      Q37-17 (RDAM) or P30-5 (DATA) - Body ground Always 10 kΩ or higher
      Q37-5 (RCO) or P30-4 (+5) - Body ground Always 10 kΩ or higher

    • OK

      REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR