CAN COMMUNICATION SYSTEM(for LHD without Entry and Start System), Diagnostic DTC:U1002

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 CAN MS bus.

• When the main body ECU (multiplex network body ECU) receives a response signal from the ECUs connected to the CAN MS bus, the main body ECU (multiplex network body ECU) recognizes and memorizes that the ECU is connected to the CAN MS bus. Based on this memorized data, the main body ECU (multiplex network body ECU) monitors for malfunctions in the ECUs connected to the CAN 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 CAN 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 [CAN branch wire]/CANL [CAN branch wire] of the ECU and/or sensor is open).

• For vehicles with a multi-function switch.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. 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 airbag system.

      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.

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

   
   

   NEXT

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

   
   
   1. 

      Text in Illustration

      *a	Component with harness connected (No. 8 Junction Connector)
      *b	Front view of DLC3

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

      Standard Resistance

      Tester Connection Switch Condition Specified Condition Resistance: Malfunction G103-3 (CANP) - G103-2 (CANN) Ignition switch off 54 to 69 Ω Below 53 Ω: Short in line G103-3 (CANP) - G103-2 (CANN) Ignition switch off 54 to 69 Ω Higher than 70 Ω: Open in CAN main bus line G103-3 (CANP) - G48-16 (BAT) Ignition switch off 6 kΩ or higher Below 6 kΩ: +B short G103-2 (CANN) - G48-16 (BAT) Ignition switch off 6 kΩ or higher Below 6 kΩ: +B short G103-3 (CANP) - G48-4 (CG) Ignition switch off 200 Ω or higher Below 200 Ω: Ground short G103-2 (CANN) - G48-4 (CG) 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 short GND short	B
      OK	C

   
   

   B

   CHECK FOR SHORT IN CAN BUS WIRES (NO. 3 JUNCTION CONNECTOR - DRIVING SUPPORT SWITCH CONTROL ECU) Click here

   C

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

   A

3. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 3 JUNCTION CONNECTOR - MAIN BODY ECU)

   
   
   1. 

      Text in Illustration

      *a	Rear view of wire harness connector (to No. 3 Junction Connector)

      Disconnect the G96 No. 3 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition G96-4 (CANH) - G96-15 (CANL) Ignition switch off 108 to 132 Ω

   
   

   NG

   CONNECT CONNECTOR Click here

   OK

4. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 3 JUNCTION CONNECTOR - NO. 8 JUNCTION CONNECTOR)

   
   
   1. 

      Text in Illustration

      *a	Rear view of wire harness connector (to No. 3 Junction Connector)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition G96-6 (CANH) - G96-17 (CANL) Ignition switch off 108 to 132 Ω

   
   

   OK

   REPLACE NO. 3 JUNCTION CONNECTOR

   NG

   CONNECT CONNECTOR Click here

5. CONNECT CONNECTOR

   
   

   1. Reconnect the G96 No. 3 junction connector.

   
   

   NEXT

6. CHECK FOR OPEN IN CAN BUS MAIN WIRE (MAIN BODY ECU)

   
   
   1. 

      Text in Illustration

      *a	Front view of wire harness connector (to Main Body ECU [Multiplex Network Body ECU])

      Disconnect the G63 main body ECU (multiplex network body ECU) connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition G63-9 (CANP) - G63-10 (CANN) Ignition switch off 108 to 132 Ω

   
   

   OK

   REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

   NG

   REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO MAIN BODY ECU (MAIN BODY ECU - NO. 3 JUNCTION JUNCTION CONNECTOR)

7. CONNECT CONNECTOR

   
   

   1. Reconnect the G96 No. 3 junction connector.

   
   

   NEXT

8. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 8 JUNCTION CONNECTOR)

   
   
   1. 

      Text in Illustration

      *a	Rear view of wire harness connector (to No. 8 Junction Connector)

      Disconnect the G103 No. 8 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition G103-3 (CANP) - G103-2 (CANN) Ignition switch off 108 to 132 Ω

   
   

   OK

   REPLACE NO. 8 JUNCTION CONNECTOR

   NG

   REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 8 JUNCTION CONNECTOR - NO. 3 JUNCTION CONNECTOR)

9. CHECK FOR SHORT IN CAN BUS WIRES (NO. 3 JUNCTION CONNECTOR - DRIVING SUPPORT SWITCH CONTROL ECU)

   
   
   1. 

      Text in Illustration

      *a	Rear view of wire harness connector (to No. 3 Junction Connector)
      *b	Front view of DLC3

      Disconnect the G96 No. 3 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition G96-5 (CANH) - G96-16 (CANL) Ignition switch off 200 Ω or higher G96-5 (CANH) - G48-4 (CG) Ignition switch off 200 Ω or higher G96-16 (CANL) - G48-4 (CG) Ignition switch off 200 Ω or higher G96-5 (CANH) - G48-16 (BAT) Ignition switch off 6 kΩ or higher G96-16 (CANL) - G48-16 (BAT) Ignition switch off 6 kΩ or higher

   
   

   NG

   CONNECT CONNECTOR Click here

   OK

10. CHECK FOR SHORT IN CAN BUS WIRES (NO. 3 JUNCTION CONNECTOR - MAIN BODY ECU)

    
    
    1. 

       Text in Illustration

       *a	Rear view of wire harness connector (to No. 3 Junction Connector)
       *b	Front view of DLC3

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

       Standard Resistance
       Tester Connection Switch Condition Specified Condition G96-4 (CANH) - G96-15 (CANL) Ignition switch off 108 to 132 Ω G96-4 (CANH) - G48-4 (CG) Ignition switch off 200 Ω or higher G96-15 (CANL) - G48-4 (CG) Ignition switch off 200 Ω or higher G96-4 (CANH) - G48-16 (BAT) Ignition switch off 6 kΩ or higher G96-15 (CANL) - G48-16 (BAT) Ignition switch off 6 kΩ or higher

    
    

    NG

    CONNECT CONNECTOR Click here

    OK

11. CHECK FOR SHORT IN CAN BUS WIRES (NO. 3 JUNCTION CONNECTOR - NO. 8 JUNCTION CONNECTOR)

    
    
    1. 

       Text in Illustration

       *a	Rear view of wire harness connector (to No. 3 Junction Connector)
       *b	Front view of DLC3

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

       Standard Resistance
       Tester Connection Switch Condition Specified Condition G96-6 (CANH) - G96-17 (CANL) Ignition switch off 108 to 132 Ω G96-6 (CANH) - G48-4 (CG) Ignition switch off 200 Ω or higher G96-17 (CANL) - G48-4 (CG) Ignition switch off 200 Ω or higher G96-6 (CANH) - G48-16 (BAT) Ignition switch off 6 kΩ or higher G96-17 (CANL) - G48-16 (BAT) Ignition switch off 6 kΩ or higher

    
    

    OK

    REPLACE NO. 3 JUNCTION CONNECTOR

    NG

    CONNECT CONNECTOR Click here

12. CONNECT CONNECTOR

    
    

    1. Reconnect the G96 No. 3 junction connector.

    
    

    NEXT

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

    
    

    1. for Automatic Transmission:

       
       
       1. 

          Text in Illustration

          *a	Front view of wire harness connector (to Driving Support Switch Control ECU)
          *b	Front view of DLC3

          Disconnect the G163 driving support switch control ECU connector.

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

          Standard Resistance
          Tester Connection Switch Condition Specified Condition G163-2 (CANP) - G163-3 (CANN) Ignition switch off 54 to 69 Ω G163-2 (CANP) - G48-4 (CG) Ignition switch off 200 Ω or higher G163-3 (CANN) - G48-4 (CG) Ignition switch off 200 Ω or higher G163-2 (CANP) - G48-16 (BAT) Ignition switch off 6 kΩ or higher G163-3 (CANN) - G48-16 (BAT) Ignition switch off 6 kΩ or higher

    2. for Manual Transmission:

       
       
       1. 

          Text in Illustration

          *a	Rear view of wire harness connector (to Driving Support Switch Control ECU)
          *b	Front view of DLC3

          Disconnect the G76 driving support switch control ECU connector.

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

          Standard Resistance
          Tester Connection Switch Condition Specified Condition G76-9 (CANP) - G76-10 (CANN) Ignition switch off 54 to 69 Ω G76-9 (CANP) - G48-4 (CG) Ignition switch off 200 Ω or higher G76-10 (CANN) - G48-4 (CG) Ignition switch off 200 Ω or higher G76-9 (CANP) - G48-16 (BAT) Ignition switch off 6 kΩ or higher G76-10 (CANN) - G48-16 (BAT) Ignition switch off 6 kΩ or higher

    
    

    OK

    REPLACE DRIVING SUPPORT SWITCH CONTROL ECU Click here

    NG

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

14. CONNECT CONNECTOR

    
    

    1. Reconnect the G96 No. 3 junction connector.

    
    

    NEXT

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

    
    
    1. 

       Text in Illustration

       *a	Front view of wire harness connector (to Main Body ECU [Multiplex Network Body ECU])
       *b	Front view of DLC3

       Disconnect the G63 main body ECU (multiplex network body ECU) connector.

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

       Standard Resistance
       Tester Connection Switch Condition Specified Condition G63-9 (CANP) - G63-10 (CANN) Ignition switch off 108 to 132 Ω G63-9 (CANP) - G48-4 (CG) Ignition switch off 200 Ω or higher G63-10 (CANN) - G48-4 (CG) Ignition switch off 200 Ω or higher G63-9 (CANP) - G48-16 (BAT) Ignition switch off 6 kΩ or higher G63-10 (CANN) - G48-16 (BAT) Ignition switch off 6 kΩ or higher

    
    

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    NG

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

16. CONNECT CONNECTOR

    
    

    1. Reconnect the G96 No. 3 junction connector.

    
    

    NEXT

17. CHECK FOR SHORT IN CAN BUS WIRES (NO. 8 JUNCTION CONNECTOR)

    
    
    1. 

       Text in Illustration

       *a	Rear view of wire harness connector (to No. 8 Junction Connector)
       *b	Front view of DLC3

       Disconnect the G103 No. 8 junction connector.

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

       Standard Resistance
       Tester Connection Switch Condition Specified Condition G103-3 (CANP) - G103-2 (CANN) Ignition switch off 108 to 132 Ω G103-3 (CANP) - G48-4 (CG) Ignition switch off 200 Ω or higher G103-2 (CANN) - G48-4 (CG) Ignition switch off 200 Ω or higher G103-3 (CANP) - G48-16 (BAT) Ignition switch off 6 kΩ or higher G103-2 (CANN) - G48-16 (BAT) Ignition switch off 6 kΩ or higher

    
    

    OK

    REPLACE NO. 8 JUNCTION CONNECTOR

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 8 JUNCTION CONNECTOR - NO. 3 JUNCTION CONNECTOR)

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

    
    

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

       Note

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

       

       Text in Illustration

       *a

       Rear view of wire harness connector (to Main Body ECU [Multiplex Network Body ECU])

       *b

       Front view of wire harness connector (to Main Body ECU [Multiplex Network Body ECU])

    2. Remove the main body ECU (multiplex network body ECU) Click here.

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

       Standard Resistance
       Tester Connection Condition Specified Condition G63-3 (GND2) - Body ground Always Below 1 Ω A-11 (GND1) - Body ground Always Below 1 Ω

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

       Standard Voltage
       Tester Connection Condition Specified Condition A-31 (ALTB) - Body ground Always 11 to 14 V A-30 (BECU) - Body ground Always 11 to 14 V A-29 (ACC) - Body ground Ignition switch ACC 11 to 14 V A-32 (IG) - Body ground Ignition switch ON 11 to 14 V

    
    

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR