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

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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
   3B-30 (LIN2) - MB-16 (LIN2)	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a

   Component without harness connected (Instrument Panel Junction Block Assembly)

   *b

   Component without harness connected (Instrument Panel Junction Block Assembly)

NG → See step   6 

OK: Go to next step 

1. Disconnect the S4 sliding roof ECU (sliding roof drive gear sub-assembly) connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3B-30 (LIN2) - S4-11 (MPX1)	Always	Below 1 Ω
   3B-30 (LIN2) - Body ground	Always	10 kΩ or higher

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.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   S4-8 (B) - S4-12 (E)	Always	11 to 14 V

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   S4-12 (E) - Body ground	Always	Below 1 Ω

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 DISASSEMBLY .

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 (SLIDING ROOF DRIVE GEAR SUB-ASSEMBLY) WAS DEFECTIVE)