Part 2

NETWORKING: CAN COMMUNICATION SYSTEM: U1002: Lost Communication with Gateway Module (MS Bus)
U1002 - Lost Communication with Gateway Module (MS Bus)

DESCRIPTION

* The main body ECU (multiplex network body ECU) stores this DTC when no signals can be received from the ECUs that have been memorized as those connected to the MS bus.

* When the main body ECU (multiplex network body ECU) receives a response signal from the ECUs connected to the MS bus, the main body ECU (multiplex network body ECU) recognizes and memorizes that the ECU is connected to the MS bus. Based on this memorized data, the main body ECU (multiplex network body ECU) monitors for malfunctions in the ECUs connected to the MS bus when communicating with those ECUs. If the main body ECU (multiplex network body ECU) cannot receive response signals from the ECUs that have been memorized as those connected to the MS bus, the main body ECU (multiplex network body ECU) determines that a malfunction exists.

* If 2 or more DTCs are output during the DTC check, one side of the CAN branch wire may be open (one side of the CANH [branch wire]/CANL [branch wire] of the ECU and/or sensor is open).





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT
Operating the engine switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.



19. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 JUNCTION CONNECTOR - DRIVING SUPPORT SWITCH CONTROL ECU)

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





Standard Resistance:





Text in Illustration





NG -- CONNECT CONNECTOR
OK -- Continue to next step.

20. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 JUNCTION CONNECTOR - OUTER MIRROR CONTROL ECU RH)

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





Standard Resistance:





Text in Illustration





NG -- CONNECT CONNECTOR
OK -- Continue to next step.

21. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 JUNCTION CONNECTOR - NO. 6 JUNCTION CONNECTOR)

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





Standard Resistance:





Text in Illustration





NG -- CONNECT CONNECTOR

OK -- REPLACE NO. 1 JUNCTION CONNECTOR

22. CONNECT CONNECTOR

(a) Reconnect the G81 No. 3 junction connector connector.

NEXT -- Continue to next step.

23. CHECK FOR SHORT IN CAN BUS WIRES (FRONT POWER SEAT SWITCH LH)

(a) Disconnect the b5 front power seat switch LH connector.





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

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO FRONT POWER SEAT SWITCH LH (CANP, CANN)

OK -- REPLACE FRONT POWER SEAT SWITCH LH Disassembly

24. CONNECT CONNECTOR

(a) Reconnect the G81 No. 3 junction connector connector.

NEXT -- Continue to next step.

25. CHECK FOR SHORT IN CAN BUS WIRES (MULTIPLEX TILT AND TELESCOPIC ECU)

(a) Disconnect the G33 multiplex tilt and telescopic ECU connector.





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

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO MULTIPLEX TILT AND TELESCOPIC ECU (CANP, CANN)

OK -- REPLACE MULTIPLEX TILT AND TELESCOPIC ECU

26. CONNECT CONNECTOR

(a) Reconnect the G81 No. 3 junction connector connector.

NEXT -- Continue to next step.

27. CHECK FOR SHORT IN CAN BUS WIRES (OUTER MIRROR CONTROL ECU LH)

(a) Disconnect the K8 outer mirror control ECU assembly LH connector.





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

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO OUTER MIRROR CONTROL ECU LH (CANP, CANN)

OK -- REPLACE OUTER MIRROR CONTROL ECU ASSEMBLY LH Removal

28. CONNECT CONNECTOR

(a) Reconnect the G81 No. 3 junction connector connector.

NEXT -- Continue to next step.

29. CHECK FOR SHORT IN CAN BUS WIRES (MAIN BODY ECU)

(a) Disconnect the G46 main body ECU (multiplex network body ECU) connector.





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

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO MAIN BODY ECU (CANP, CANN)

OK -- REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Removal

30. CONNECT CONNECTOR

(a) Reconnect the G84 No. 1 junction connector connector.

NEXT -- Continue to next step.

31. CHECK FOR SHORT IN CAN BUS WIRES (DRIVING SUPPORT SWITCH CONTROL ECU)

(a) Disconnect the G60 driving support switch control ECU connector.





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

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DRIVING SUPPORT SWITCH CONTROL ECU (CANP, CANN)

OK -- REPLACE DRIVING SUPPORT SWITCH CONTROL ECU Removal

32. CONNECT CONNECTOR

(a) Reconnect the G84 No. 1 junction connector connector.

NEXT -- Continue to next step.

33. CHECK FOR SHORT IN CAN BUS WIRES (OUTER MIRROR CONTROL ECU RH)

(a) Disconnect the J8 outer mirror control ECU assembly RH connector.





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

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO OUTER MIRROR CONTROL ECU RH (CANP, CANN)

OK -- REPLACE OUTER MIRROR CONTROL ECU ASSEMBLY RH Removal

34. CONNECT CONNECTOR

(a) Reconnect the G84 No. 1 junction connector connector.

NEXT -- Continue to next step.

35. CHECK FOR SHORT IN CAN BUS WIRES (NO. 6 JUNCTION CONNECTOR)

(a) Disconnect the G87 No. 6 junction connector connector.





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

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 6 JUNCTION CONNECTOR - NO. 1 JUNCTION CONNECTOR)

OK -- REPLACE NO. 6 JUNCTION CONNECTOR

36. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BATTERY AND GROUND)

(a) Connect the cable to the negative (-) battery terminal.





Text in Illustration





NOTICE:
When disconnecting the cable, some systems need to be initialized after the cable is reconnected Repair Instruction - Initialization.

(b) Remove the main body ECU (multiplex network body ECU) Removal.

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

Standard Resistance:





(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Removal