DTC    B1273    Sliding Roof ECU Communication Stop

for Preparation Click here


DESCRIPTION

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

DTC No.
DTC Detection Condition
Trouble Area
B1273
Sliding roof control ECU communication stops
  1. Sliding roof control ECU
  2. Wire harness

WIRING DIAGRAM


B110981E02


INSPECTION PROCEDURE

HINT:
When "+B of GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTCB1273, repair the "+B or GND short malfunction of communication bus" DTCs first.

1.CHECK OPERATION

  1. Check that the tilt or slide switch can operate the sliding roof normally.

    HINT:
    With this inspection, the sliding roof dive gear (sliding roof control ECU) CPU can be diagnosed if it works normally or not.

    OK:
    Tilt or slide switch can operate sliding roof normally.



OK
Go to step 4
NG


2.INSPECT FUSE (S/ROOF)

  1. Remove the S/ROOF fuse from the instrument panel block.

  1. Measure the resistance of the fuse.

    Standard resistance:
    Below 1 Ω



NG
REPLACE FUSE
OK


3.INSPECT WIRE HARNESS (SLIDING ROOF CONTROL ECU - BATTERY AND BODY GROUND)


    B109188E06

  1. Disconnect the M5 ECU connector.

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

    Standard voltage:
    Tester Connection
    		Specified Condition
    M5-1 (B) - Body ground
    		10 to 14 V

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

    Standard resistance:
    Tester Connection
    		Specified Condition
    M5-7 (E) - Body ground
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.CHECK RESISTANCE OF COMMUNICATION LINE

  1. Disconnect the G1 and C8 ECU connectors (w/ LEXUS navigation system).



  1. Disconnect the C4 and C8 ECU connectors (w/o LEXUS navigation system).


    B111057E02

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

    Standard resistance:

    Tester Connection
    		Specified Condition
    M5-10 (MPX1) - G1-13 (MPI2) (*1)
    		Below 1 Ω
    M5-10 (MPX1) - C4-12 (MPX-) (*2)
    		Below 1 Ω
    M5-10 (MPX1) - C8-5 (MPX+)
    		Below 1 Ω

    *1: w/ LEXUS Navigation System
    *2: w/o LEXUS Navigation System



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR OR OVERHEAD J/B
OK

REPLACE SLIDING ROOF CONTROL ECU