Dtc B1242 Wireless Door Lock Tuner Circuit Malfunction


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

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

CHECK CERTIFICATION ECU

REPLACE DOOR CONTROL RECEIVER

CLEAR DTC

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 decodes the requested entry and start 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. The certification ECU then sends a command, according to the requested operation, to each ECU (ex.: if a door lock operation is requested, the certification ECU sends a door lock command to the main body ECU).
This DTC is stored when both of the following occurs: 1) a short from RDA or RSSI to ground between the certification ECU and the door control receiver, and 2) RCO output (5 V) from the ECU is off.

DTC Code
DTC Detection Condition
Trouble Area
B1242
Both conditions are met:
  1. A short from RDA or RSSI to ground between the certification ECU and door control receiver.
  2. RCO output (5 V) from the ECU is off.
  1. Harness or connector
  2. Door control receiver
  3. Certification ECU

WIRING DIAGRAM


Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Door Lock.Power Door Lock Control System. Dtc B1242 Wireless Door Lock Tuner Circuit Malfunction


INSPECTION PROCEDURE

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.
  3. When using the intelligent tester with the engine switch off to troubleshoot: Connect the intelligent tester to the DLC3 and turn a courtesy light switch on and off at 1.5-second intervals until communication between the tester and vehicle begins.
  4. Before replacing the certification ECU, refer to the Service Bulletin.
1.CHECK HARNESS AND CONNECTOR (DOOR CONTROL RECEIVER - CERTIFICATION ECU AND BODY GROUND)

  1. Disconnect the R17 receiver connector.

  1. Disconnect the G38 and G39 ECU connectors.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    R17-2 (RSSI) - G39-16 (RSSI)
    		Always
    		Below 1 Ω
    R17-5 (DATA) - G39-15 (RDA)
    		Always
    		Below 1 Ω
    R17-4 (+5) - G39-5 (RCO)
    		Always
    		Below 1 Ω
    R17-1 (GND) - Body ground
    		Always
    		Below 1 Ω
    G38-15 (E) - Body ground
    		Always
    		Below 1 Ω
    R17-2 (RSSI) or G39-16 (RSSI) - Body ground
    		Always
    		10 kΩ or higher
    R17-5 (DATA) or G39-15 (RDA) - Body ground
    		Always
    		10 kΩ or higher
    R17-4 (+5) or G39-5 (RCO) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


2.CHECK CERTIFICATION ECU


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


    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Door Lock.Power Door Lock Control System. Dtc B1242 Wireless Door Lock Tuner Circuit Malfunction


    Text in Illustration
    *a
    		Component with harness connected
    (Certification ECU)
    		-
    		-
    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    G39-5 (RCO) - G38-15 (E)
    		Engine switch off, all doors closed and transmitter switch not pressed → pressed
    		Below 1 V → 4.5 to 5.5 V


NG
REPLACE CERTIFICATION ECU
OK


3.REPLACE DOOR CONTROL RECEIVER

  1. Temporarily replace the door control receiver with a new or normally functioning one.

    1. for 5 Door: (LandCruiser RM0000046JL02MX.html).
    2. for 3 Door: (LandCruiser RM0000046JQ00VX.html).

NEXT


4.CLEAR DTC

  1. Clear the DTCs (LandCruiser RM000002BZF06QX.html).


NEXT


5.CHECK FOR DTC

  1. Check for DTCs (LandCruiser RM000002BZF06QX.html).

    OK:
    DTC B1242 is not output.


NG
REPLACE CERTIFICATION ECU
OK

END (DOOR CONTROL RECEIVER IS DEFECTIVE)