DTC    B1273    Sliding Roof ECU Communication Stop

for Preparation Click here


DESCRIPTION

This DTC is output when LIN communication between the sliding roof ECU (sliding roof drive gear sub-assembly) and main body ECU (instrument panel junction block) stops for more than 10 seconds.

DTC No.
DTC Detection Condition
Trouble Area
B1273
No communication between sliding roof ECU (Sliding roof drive gear sub-assembly) and main body ECU (Instrument panel junction block) for more than 10 seconds
  1. Sliding roof ECU (Sliding roof drive gear sub-assembly)
  2. Main body ECU (Instrument panel junction block)
  3. Wire harness or connector

WIRING DIAGRAM


B176995E24


INSPECTION PROCEDURE

NOTICE:
When using the intelligent tester with the ignition switch off to troubleshoot:
Connect the intelligent tester to the vehicle, and turn the courtesy switch on and off at 1.5-second intervals until communication between the tester and vehicle begins.
1.CLEAR DTC
  1. Clear the DTC (Click here).


NEXT


2.CHECK DTC OUTPUT
  1. Recheck for DTC (Click here).

    Result:
    Result
    Proceed to
    B1273 is output
    A
    B1273 is not output
    B


B
USE SIMULATION METHOD TO CHECK (Click here)
A


3.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - SLIDING ROOF ECU)


  1. Disconnect the E8 and Q12 connectors.


    B178901E02

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

    Standard resistance:
    Tester Connection
    Condition
    Specified Condition
    E8-10 (LIN2) - Q12-4 (MPX1)
    Always
    Below 1 Ω
    E8-10 (LIN2) - Body ground
    Always
    10 kΩ or higher
  1. Measure the voltage according to the value(s) in the table below.

    Standard voltage:
    Tester Connection
    Condition
    Specified Condition
    E8-10 (LIN2) - Body ground
    Always
    Below 1 V


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.CHECK HARNESS AND CONNECTOR (SLIDING ROOF ECU - BATTERY AND GROUND)


    B164448E06
  1. Measure the resistance according to the value(s) in the table below.

    Standard resistance:
    Tester Connection
    Condition
    Specified Condition
    Q12-2 (E) - Body ground
    Always
    Below 1 Ω
  1. Measure the voltage according to the value(s) in the table below.

    Standard voltage:
    Tester Connection
    Condition
    Specified Condition
    Q12-1 (B) - Body ground
    Always
    11 to 14 V


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.REPLACE SLIDING ROOF ECU (SLIDING ROOF DRIVE GEAR SUB-ASSEMBLY)
  1. Replace the sliding roof ECU (Sliding roof drive gear sub-assembly) (Click here).


NEXT


6.CHECK DTC OUTPUT
  1. Clear the DTC (Click here).

  1. Recheck for DTC.

    Result:
    Result
    Proceed to
    B1273 is not output
    A
    B1273 is output
    B


B
REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)
A

END (SLIDING ROOF ECU IS DEFECTIVE)