Dtc B1249 Double Locking Ecu Communication Stop

Communication System. Lexus Is250, Is220D. Gse20 Ale20
Multiplex Communication. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT FUSE (MPX-B, DOOR DL)

CHECK WIRE HARNESS (DOUBLE DOOR LOCK ECU - BATTERY AND BODY GROUND)

CHECK COMMUNICATION LINE

DTC B1249 Double Locking ECU Communication Stop


DESCRIPTION

  1. This DTC is detected when communication between the double door lock ECU and gateway ECU stops for more than 10 seconds.

DTC No.
DTC Detection Condition
Trouble Area
B1262
Double door lock ECU communication stops
  1. Double door lock ECU
  2. Wire harness

WIRING DIAGRAM


Lexus Is250, Is220D. Gse20 Ale20.Multiplex Communication.Multiplex Communication System. Dtc B1249 Double Locking Ecu Communication Stop


INSPECTION PROCEDURE

HINT:
When "+B of GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1249, repair the "+B or GND short malfunction of communication bus" DTCs first.
1.INSPECT FUSE (MPX-B, DOOR DL)

  1. Remove the MPX-B fuse from the engine room J/B No. 1.

  1. Remove the DOOR DL fuse from the main body ECU RH (cowl side J/B RH).

  1. Measure the resistance of the fuse.

    Standard resistance:
    Below 1 Ω


NG
REPLACE FUSE
OK


2.CHECK WIRE HARNESS (DOUBLE DOOR LOCK ECU - BATTERY AND BODY GROUND)


    Lexus Is250, Is220D. Gse20 Ale20.Multiplex Communication.Multiplex Communication System. Dtc B1249 Double Locking Ecu Communication Stop

  1. Disconnect the P34 ECU connector.

  1. Measure the voltage and resistance of the wire harness side connector.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    +B (P34-1) - Body ground
    		Always
    		10 to 14 V
    CPUB (P34-7) - Body ground
    		Always
    		10 to 14 V
    Standard resistance:
    Tester Connection
    		Specified Condition
    GND (P34-14) - Body ground
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK COMMUNICATION LINE


    Lexus Is250, Is220D. Gse20 Ale20.Multiplex Communication.Multiplex Communication System. Dtc B1249 Double Locking Ecu Communication Stop

  1. Disconnect the P34 and P33 ECU connectors.

  1. Measure the resistance of the wire harness side connector.

    Standard resistance:
    Tester Connection
    		Specified Condition
    MPX1 (P34-9) - MPX1 (P33-27)
    		Below 1 Ω
    MPX1 (P34-9) - Body ground
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE DOUBLE DOOR LOCK ECU