DTC B1273: Sliding Roof ECU Communication Stop: Procedure

1. Remove the instrument panel junction block assembly. Refer to REMOVAL .
   Fig 1: Inspecting Instrument Panel Junction Block Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
3. Measure the resistance according to the value(s) in the table below.

   HINT: 

   This inspection is to check the LIN line in the instrument panel junction block assembly that connects the wire harness to the built-in main body ECU (multiplex network body ECU).

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   2A-27 (LIN2)- MB-16 (LIN2)	Always	Below 1 Ω
   2A-27 (LIN2) - Body ground	Always	10 kΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *1

   Component without harness connected (Instrument Panel Junction Block Assembly)

   *2

   Component without harness connected (Instrument Panel Junction Block Assembly)

NG → See step   6 

OK: Go to next step 

1. Disconnect the R23 sliding roof ECU (sliding roof drive gear sub-assembly) connector.
   Fig 2: Identifying Instrument Panel Junction Block And Sliding Roof ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   2A-27 (LIN2) - R23-4 (MPX1)	Always	Below 1 Ω
   2A-27 (LIN2) - Body ground	Always	10 kΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Instrument Panel Junction Block Assembly)
   *2	Front view of wire harness connector (to Sliding Roof ECU (Sliding Roof Drive Gear Sub-assembly))

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.
   Fig 3: Identifying Sliding Roof ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   R23-1 (B) - R23-2 (E)	Power switch off	11 to 14 V

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   R23-2 (E) - Body ground	Always	10 kΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Sliding Roof ECU (Sliding Roof Drive Gear Sub-assembly))

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Replace the sliding roof ECU (sliding roof drive gear sub-assembly). Refer to REMOVAL .

NEXT: Go to next step 

1. Clear the DTC. Refer to DTC CHECK / CLEAR .
2. Recheck for DTCs.

   OK

   DTC B1273 is not output.

NG → See step   7 

OK → END (SLIDING ROOF ECU WAS DEFECTIVE)