CAN COMMUNICATION SYSTEM, Diagnostic DTC:U1002

DESCRIPTION

• The main body ECU stores this DTC when no signals can be received from the ECUs that have been memorized as those connected to the CAN MS bus.

  Tech Tips

  DTCs indicating a CAN MS bus malfunction are only stored for vehicles with a seat position memory system. If the vehicle is equipped with a seat position memory system, it is also equipped with a power tilt and power telescopic steering column system.

• When the main body ECU receives a response signal from an ECU connected to the CAN MS bus, the main body ECU recognizes and memorizes that the ECU is connected to the CAN MS bus. Based on this memorized data, the main body ECU monitors for malfunctions in the ECUs connected to the CAN MS bus when communicating with those ECUs. If the main body ECU cannot receive response signals from the ECUs that have been memorized as those connected to the CAN MS bus, the main 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 [CAN branch wire]/CANL [CAN branch wire] of the ECU and/or sensor is open).

• *: w/ Seat Position Memory System

• For vehicles for power tilt and power telescopic steering column.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. PRECAUTION

   Note

   After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work Click here.

   
   

   NEXT

2. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL

   
   

   1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.

   
   

   NEXT

3. CHECK CAN BUS WIRE (CAN MAIN WIRE FOR DISCONNECTION, CHECK BUS LINE FOR SHORT CIRCUIT)

   
   
   1. 

      Text in Illustration

      *a	Component with harness connected (Multiplex Tilt and Telescopic ECU)

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

      Standard Resistance

      Tester Connection Switch Condition Specified Condition Resistance: Malfunction D45-5 (CANP) - D45-14 (CANN) Ignition switch off 54 to 69 Ω Below 54 Ω: Short in line D45-5 (CANP) - D45-14 (CANN) Ignition switch off 54 to 69 Ω Higher than 69 Ω: Open in CAN main bus line D45-5 (CANP) - D45-2 (+B) Ignition switch off 6 kΩ or higher Below 6 kΩ: +B short D45-14 (CANN) - D45-2 (+B) Ignition switch off 6 kΩ or higher Below 6 kΩ: +B short D45-5 (CANP) - D45-11(GND) Ignition switch off 200 Ω or higher Below 200 Ω: Ground short D45-14 (CANN) - D45-11(GND) Ignition switch off 200 Ω or higher Below 200 Ω: Ground short

      Result

      Result	Proceed to
      NG Open in CAN main bus line	A
      NG Short in line +B line GND line	B
      OK	C

   
   

   B

   CHECK FOR SHORT IN CAN BUS WIRE (NO. 5 JUNCTION CONNECTOR - POSITION CONTROL ECU ASSEMBLY) Click here

   C

   CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BATTERY AND BODY GROUND) Click here

   A

4. CHECK FOR OPEN IN CAN BUS WIRE (NO. 5 JUNCTION CONNECTOR - MULTIPLEX TILT AND TELESCOPIC ECU)

   
   
   1. 

      Text in Illustration

      *A	for LHD
      *B	for RHD
      *a	Rear view of wire harness connector (to No. 5 Junction Connector)

      Disconnect the G42*1 or H21*2 No. 5 junction connector.

      
      

      • *1: for LHD

      • *2: for RHD

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

      Standard Resistance
      for LHD Tester Connection Switch Condition Specified Condition G42-2 (CANH) - G42-13 (CANL) Ignition switch off 108 to 132 Ω
      for RHD Tester Connection Switch Condition Specified Condition H21-2 (CANH) - H21-13 (CANL) Ignition switch off 108 to 132 Ω

   
   

   NG

   CONNECT CONNECTOR Click here

   OK

5. CHECK FOR OPEN IN CAN BUS WIRE (NO. 5 JUNCTION CONNECTOR - MAIN BODY ECU)

   
   
   1. 

      Text in Illustration

      *A	for LHD
      *B	for RHD
      *a	Rear view of wire harness connector (to No. 5 Junction Connector)

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

      Standard Resistance
      for LHD Tester Connection Switch Condition Specified Condition G42-3 (CANH) - G42-14 (CANL) Ignition switch off 108 to 132 Ω
      for RHD Tester Connection Switch Condition Specified Condition H21-3 (CANH) - H21-14 (CANL) Ignition switch off 108 to 132 Ω

   
   

   NG

   CONNECT CONNECTOR Click here

   OK

   REPLACE NO. 5 JUNCTION CONNECTOR

6. CONNECT CONNECTOR

   
   

   1. Reconnect the G42*1 or H21*2 No. 5 junction connector.

      
      

      • *1: for LHD

      • *2: for RHD

   
   

   NEXT

7. CHECK FOR OPEN IN CAN BUS WIRE (MULTIPLEX TILT AND TELESCOPIC ECU - NO. 5 JUNCTION CONNECTOR)

   
   
   1. 

      Text in Illustration

      *a	Rear view of wire harness connector (to Multiplex Tilt and Telescopic ECU)

      Disconnect the D45 multiplex tilt and telescopic ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition D45-5 (CANP) - D45-14 (CANN) Ignition switch off 108 to 132 Ω

   
   

   NG

   REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO MULTIPLEX TILT AND TELESCOPIC ECU (MULTIPLEX TILT AND TELESCOPIC ECU - NO. 5 JUNCTION CONNECTOR)

   OK

   REPLACE MULTIPLEX TILT AND TELESCOPIC ECU Click here

8. CONNECT CONNECTOR

   
   

   1. Reconnect the G42*1 or H21*2 No. 5 junction connector.

      
      

      • *1: for LHD

      • *2: for RHD

   
   

   NEXT

9. CHECK FOR OPEN IN CAN BUS WIRE (MAIN BODY ECU - NO. 5 JUNCTION CONNECTOR)

   
   
   1. 

      Text in Illustration

      *a	Front view of wire harness connector (to Main Body ECU [Instrument Panel Junction Block Assembly])

      Disconnect the D80 main body ECU (instrument panel junction block assembly) connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition D80-3 (CANP) - D80-2 (CANN) Ignition switch off 108 to 132 Ω

   
   

   NG

   REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO MAIN BODY ECU (MAIN BODY ECU - NO. 5 JUNCTION CONNECTOR)

   OK

   REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

10. CHECK FOR SHORT IN CAN BUS WIRE (NO. 5 JUNCTION CONNECTOR - POSITION CONTROL ECU ASSEMBLY)

    Note

    For vehicles without an seat position memory system, go to "Check for Short in CAN Bus Wire (No. 5 Junction Connector - Multiplex Tilt and Telescopic ECU)"

    
    
    1. 

       Text in Illustration

       *A	for LHD
       *B	for RHD
       *a	Rear view of wire harness connector (to No. 5 Junction Connector)
       *b	Front view of DLC3

       Disconnect the G42*1 or H21*2 No. 5 junction connector.

       
       

       • *1: for LHD

       • *2: for RHD

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

       Standard Resistance
       for LHD Tester Connection Switch Condition Specified Condition G42-1 (CANH) - G42-12 (CANL) Ignition switch off 200 Ω or higher G42-1 (CANH) - D8-4 (CG) Ignition switch off 200 Ω or higher G42-12 (CANL) - D8-4 (CG) Ignition switch off 200 Ω or higher G42-1 (CANH) - D8-16 (BAT) Ignition switch off 6 kΩ or higher G42-12 (CANL) - D8-16 (BAT) Ignition switch off 6 kΩ or higher
       for RHD Tester Connection Switch Condition Specified Condition H21-1 (CANH) - H21-12 (CANL) Ignition switch off 200 Ω or higher H21-1 (CANH) - D8-4 (CG) Ignition switch off 200 Ω or higher H21-12 (CANL) - D8-4 (CG) Ignition switch off 200 Ω or higher H21-1 (CANH) - D8-16 (BAT) Ignition switch off 6 kΩ or higher H21-12 (CANL) - D8-16 (BAT) Ignition switch off 6 kΩ or higher

    
    

    NG

    CONNECT CONNECTOR Click here

    OK

11. CHECK FOR SHORT IN CAN BUS WIRE (NO. 5 JUNCTION CONNECTOR - MULTIPLEX TILT AND TELESCOPIC ECU)

    
    
    1. 

       Text in Illustration

       *A	for LHD
       *B	for RHD
       *a	Rear view of wire harness connector (to No. 5 Junction Connector)
       *b	Front view of DLC3

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

       Standard Resistance
       for LHD Tester Connection Switch Condition Specified Condition G42-2 (CANH) - G42-13 (CANL) Ignition switch off 108 to 132 Ω G42-2 (CANH) - D8-4 (CG) Ignition switch off 200 Ω or higher G42-13 (CANL) - D8-4 (CG) Ignition switch off 200 Ω or higher G42-2 (CANH) - D8-16 (BAT) Ignition switch off 6 kΩ or higher G42-13 (CANL) - D8-16 (BAT) Ignition switch off 6 kΩ or higher
       for RHD Tester Connection Switch Condition Specified Condition H21-2 (CANH) - H21-13 (CANL) Ignition switch off 108 to 132 Ω H21-2 (CANH) - D8-4 (CG) Ignition switch off 200 Ω or higher H21-13 (CANL) - D8-4 (CG) Ignition switch off 200 Ω or higher H21-2 (CANH) - D8-16 (BAT) Ignition switch off 6 kΩ or higher H21-13 (CANL) - D8-16 (BAT) Ignition switch off 6 kΩ or higher

    
    

    NG

    CONNECT CONNECTOR Click here

    OK

12. CHECK FOR SHORT IN CAN BUS WIRE (NO. 5 JUNCTION CONNECTOR - MAIN BODY ECU)

    
    
    1. 

       Text in Illustration

       *A	for LHD
       *B	for RHD
       *a	Rear view of wire harness connector (to No. 5 Junction Connector)
       *b	Front view of DLC3

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

       Standard Resistance
       for LHD Tester Connection Switch Condition Specified Condition G42-3 (CANH) - G42-14 (CANL) Ignition switch off 108 to 132 Ω G42-3 (CANH) - D8-4 (CG) Ignition switch off 200 Ω or higher G42-14 (CANL) - D8-4 (CG) Ignition switch off 200 Ω or higher G42-3 (CANH) - D8-16 (BAT) Ignition switch off 6 kΩ or higher G42-14 (CANL) - D8-16 (BAT) Ignition switch off 6 kΩ or higher
       for RHD Tester Connection Switch Condition Specified Condition H21-3 (CANH) - H21-14 (CANL) Ignition switch off 108 to 132 Ω H21-3 (CANH) - D8-4 (CG) Ignition switch off 200 Ω or higher H21-14 (CANL) - D8-4 (CG) Ignition switch off 200 Ω or higher H21-3 (CANH) - D8-16 (BAT) Ignition switch off 6 kΩ or higher H21-14 (CANL) - D8-16 (BAT) Ignition switch off 6 kΩ or higher

    
    

    NG

    CONNECT CONNECTOR Click here

    OK

    REPLACE NO. 5 JUNCTION CONNECTOR

13. CONNECT CONNECTOR

    
    

    1. Reconnect the G42*1 or H21*2 No. 5 junction connector.

       
       

       • *1: for LHD

       • *2: for RHD

    
    

    NEXT

14. CHECK FOR SHORT IN CAN BUS WIRE (POSITION CONTROL ECU ASSEMBLY)

    
    
    1. 

       Text in Illustration

       *A	for LHD
       *B	for RHD
       *a	Rear view of wire harness connector (to Position Control ECU Assembly)
       *b	Front view of DLC3

       Disconnect the O26*1 or O16*2 position control ECU assembly connector.

       
       

       • *1: for LHD

       • *2: for RHD

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

       Standard Resistance
       for LHD Tester Connection Switch Condition Specified Condition O26-40 (CANH) - O26-39 (CANL) Ignition switch off 54 to 69 Ω O26-40 (CANH) - D8-4 (CG) Ignition switch off 200 Ω or higher O26-39 (CANL) - D8-4 (CG) Ignition switch off 200 Ω or higher O26-40 (CANH) - D8-16 (BAT) Ignition switch off 6 kΩ or higher O26-39 (CANL) - D8-16 (BAT) Ignition switch off 6 kΩ or higher
       for RHD Tester Connection Switch Condition Specified Condition O16-40 (CANH) - O16-39 (CANL) Ignition switch off 54 to 69 Ω O16-40 (CANH) - D8-4 (CG) Ignition switch off 200 Ω or higher O16-39 (CANL) - D8-4 (CG) Ignition switch off 200 Ω or higher O16-40 (CANH) - D8-16 (BAT) Ignition switch off 6 kΩ or higher O16-39 (CANL) - D8-16 (BAT) Ignition switch off 6 kΩ or higher

    
    

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO POSITION CONTROL ECU ASSEMBLY (CANH, CANL)

    OK

    REPLACE POSITION CONTROL ECU ASSEMBLY Click here

15. CONNECT CONNECTOR

    
    

    1. Reconnect the G42*1 or H21*2 No. 5 junction connector.

       
       

       • *1: for LHD

       • *2: for RHD

    
    

    NEXT

16. CHECK FOR SHORT IN CAN BUS WIRE (MULTIPLEX TILT AND TELESCOPIC ECU)

    
    
    1. 

       Text in Illustration

       *a	Rear view of wire harness connector (to Multiplex Tilt and Telescopic ECU)
       *b	Front view of DLC3

       Disconnect the D45 multiplex tilt and telescopic ECU connector.

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

       Standard Resistance
       Tester Connection Switch Condition Specified Condition D45-5 (CANP) - D45-14 (CANN) Ignition switch off 108 to 132 Ω D45-5 (CANP) - D8-4 (CG) Ignition switch off 200 Ω or higher D45-14 (CANN) - D8-4 (CG) Ignition switch off 200 Ω or higher D45-5 (CANP) - D8-16 (BAT) Ignition switch off 6 kΩ or higher D45-14 (CANN) - D8-16 (BAT) Ignition switch off 6 kΩ or higher

    
    

    NG

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

    OK

    REPLACE MULTIPLEX TILT AND TELESCOPIC ECU Click here

17. CONNECT CONNECTOR

    
    

    1. Reconnect the G42*1 or H21*2 No. 5 junction connector.

       
       

       • *1: for LHD

       • *2: for RHD

    
    

    NEXT

18. CHECK FOR SHORT IN CAN BUS WIRE (MAIN BODY ECU)

    
    
    1. 

       Text in Illustration

       *a	Front view of wire harness connector (to Main Body ECU [Instrument Panel Junction Block Assembly])
       *b	Front view of DLC3

       Disconnect the D80 main body ECU (instrument panel junction block assembly) connector.

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

       Standard Resistance
       Tester Connection Switch Condition Specified Condition D80-3 (CANP) - D80-2 (CANN) Ignition switch off 108 to 132 Ω D80-3 (CANP) - D8-4 (CG) Ignition switch off 200 Ω or higher D80-2 (CANN) - D8-4 (CG) Ignition switch off 200 Ω or higher D80-3 (CANP) - D8-16 (BAT) Ignition switch off 6 kΩ or higher D80-2 (CANN) - D8-16 (BAT) Ignition switch off 6 kΩ or higher

    
    

    NG

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

    OK

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

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

    
    

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

       

       Text in Illustration

       *a

       Front view of wire harness connector (to Main Body ECU [Instrument Panel Junction Block Assembly])

       -

       -

       Note

       When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.

    2. Disconnect the D79, D80, DB, DE, DF and DG main body ECU (instrument panel junction block assembly) connectors.

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

       Standard Voltage
       Tester Connection Condition Specified Condition D79-4 (BATB) - Body ground Always 11 to 14 V DB-30 (BECU) - Body ground Always 11 to 14 V DF-5 (ACC) - Body ground Ignition switch ACC 11 to 14 V DG-1 (ALTB) - Body ground Always 11 to 14 V DG-1 (IG) - Body ground Always 11 to 14 V

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

       Standard Resistance
       Tester Connection Condition Specified Condition DE-17 (GND1) - Body ground Always Below 1 Ω D80-4 (GND2) - Body ground Always Below 1 Ω

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)