Lexus IS250 IS220d GSE20 ALE20 - MULTIPLEX COMMUNICATION

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT FUSE (S/ROOF)

CHECK WIRE HARNESS (SLIDING ROOF CONTROL ECU - BATTERY AND BODY GROUND)

CHECK RESISTANCE OF COMMUNICATION LINE

DTC B1273 Sliding Roof ECU Communication Stop

DESCRIPTION

This DTC is detected when communication between the sliding roof control ECU and gateway ECU stops for more than 10 seconds.

DTC No.DTC Detection ConditionTrouble Area
B1273Sliding roof control ECU communication stops
Sliding roof control ECU
Wire harness

WIRING DIAGRAM

Dtc B1273  Sliding Roof Ecu Communication Stop. MULTIPLEX COMMUNICATION. Lexus IS250 IS220d GSE20 ALE20

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" DTCB1273, repair the "+B or GND short malfunction of communication bus" DTCs first.
1.INSPECT FUSE (S/ROOF)

Remove the S/ROOF fuse from the main body ECU LH (cowl side J/B LH).

Measure the resistance of the fuse.

  • Standard resistance:
  • Below 1 Ω
NG
REPLACE FUSE
OK
2.CHECK WIRE HARNESS (SLIDING ROOF CONTROL ECU - BATTERY AND BODY GROUND)
Dtc B1273  Sliding Roof Ecu Communication Stop. MULTIPLEX COMMUNICATION. Lexus IS250 IS220d GSE20 ALE20

Disconnect the R6 ECU connector.

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

  • Standard voltage:
  • Tester ConnectionConditionSpecified Condition
    B (R6-5) - Body groundAlways10 to 14 V
  • Standard resistance:
  • Tester ConnectionSpecified Condition
    E (R6-7) - Body groundBelow 1 Ω
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
3.CHECK RESISTANCE OF COMMUNICATION LINE
Dtc B1273  Sliding Roof Ecu Communication Stop. MULTIPLEX COMMUNICATION. Lexus IS250 IS220d GSE20 ALE20

Disconnect the R6 and R5 connectors.

Measure the resistance between the specified terminals on the wire harness side connectors.

  • Standard resistance:
  • Tester ConnectionSpecified Condition
    MPX1 (R6-10) - MPX2 (R5-38)Below 1 Ω
    MPX1 (R6-10) - Body ground10 kΩ or higher
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
REPLACE SLIDING ROOF CONTROL ECU