Dtc B1242 Wireless Door Lock Tuner Circuit Malfunction

Vehicle Interior. Land Cruiser. Urj200, 202 Grj200 Vdj200
Door Lock. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

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

CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

REPLACE DOOR CONTROL RECEIVER

CHECK FOR DTC

DTC B1242 Wireless Door Lock Tuner Circuit Malfunction


DESCRIPTION

The door lock receiver is used to receive electrical waves relating to the entry functions of the entry and start system (for Entry Function). The certification ECU (smart key ECU assembly) decodes the requested smart key system (for Entry Function) 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 door control transmitter 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).
This DTC is output when one of the following occurs: 1) a short in RDA or RSSI to ground between the certification ECU and the door control receiver, or 2) a short in RDA or RSSI to ground when RCO (5 V) output from the ECU is off.
NOTICE:
  1. 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.
  2. Before performing the inspection, check that there are no problems related to the CAN communication system and LIN communication system.
  3. When using the intelligent tester with the engine switch off to troubleshoot: Connect the intelligent tester to the vehicle, and turn the front door courtesy light switch LH on and off at 1.5 second intervals until communication between the intelligent tester and vehicle begins.

DTC Code
DTC Detection Condition
Trouble Area
B1242
One of following conditions is met:
  1. Short in RDA or RSSI to ground between the certification ECU (smart key ECU assembly) and the door control receiver.
  2. Short in RDA or RSSI to ground when RCO (5 V) output from the ECU is off.
  1. Harness or connector
  2. Door control receiver
  3. Certification ECU (smart key ECU assembly)

WIRING DIAGRAM


Land Cruiser. Urj200, 202 Grj200 Vdj200.Door Lock.Power Door Lock Control System. Dtc B1242 Wireless Door Lock Tuner Circuit Malfunction


INSPECTION PROCEDURE

1.CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - DOOR CONTROL RECEIVER)


    Land Cruiser. Urj200, 202 Grj200 Vdj200.Door Lock.Power Door Lock Control System. Dtc B1242 Wireless Door Lock Tuner Circuit Malfunction

  1. Disconnect the E29 ECU connector.

  1. Disconnect the L21 receiver connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    E29-39 (RSSI) - L21-2 (RSSI)
    		Always
    		Below 1 Ω
    E29-38 (RDA) - L21-5 (DATA)
    E29-29 (RCO) - L21-4 (+5)
    E29-17 (E) - Body ground
    L21-1 (GND) - Body ground
    E29-39 (RSSI) or L21-2 (RSSI) - Body ground
    		Always
    		10 kΩ or higher
    E29-38 (RDA) or L21-5 (DATA) - Body ground
    E29-29 (RCO) or L21-4 (+5) - Body ground


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


2.CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    Land Cruiser. Urj200, 202 Grj200 Vdj200.Door Lock.Power Door Lock Control System. Dtc B1242 Wireless Door Lock Tuner Circuit Malfunction

  1. Disconnect the L21 receiver connector.

  1. Reconnect the E29 ECU connector.

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    L21-4 (+5) - Body ground
    		Always
    		4.5 to 5.4 V


NG
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
OK


3.REPLACE DOOR CONTROL RECEIVER

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


NEXT


4.CHECK FOR DTC

  1. Clear the DTC (Click here).

  1. Recheck for DTC (Click here).

    OK:
    DTC B1242 is not output.


NG
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
OK

END (DOOR CONTROL RECEIVER IS DEFECTIVE)