CAN COMMUNICATION SYSTEM > Check CAN Bus Line

for Preparation Click here


DESCRIPTION

When any DTC for the CAN communication system is output, first measure the resistance between the terminals of the DLC3 to determine the trouble area, and check that there is no short in the CAN main wire, between the CAN bus lines, to +B, or to GND.

WIRING DIAGRAM


E175971E03


E176011E02


E190634E02


E190635E02


INSPECTION PROCEDURE

NOTICE:
  1. Turn the ignition switch off before measuring the resistances of the CAN main wire and the CAN branch wire.
  2. After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not in operation.
  3. Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches or the doors. If doors need to be opened in order to check connectors, open the doors and leave them open.

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

1.SYSTEM CHECK

  1. Check the vehicle specifications.
    Result 
    Result
    		Proceed to
    w/o Stop and Start System
    		A
    w/ Stop and Start System
    		B



B
Go to step 5
A


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

  1. Turn the ignition switch off.



    E175996E01

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    		Proceed to
    D47-6 (CANH) - D47-14 (CANL)
    		Ignition switch off
    		54 to 69 Ω
    		A
    D47-6 (CANH) - D47-14 (CANL)
    		Ignition switch off
    		70 Ω or higher
    		B
    D47-6 (CANH) - D47-14 (CANL)
    		Ignition switch off
    		53 Ω or less
    		C

    Text in Illustration 
    *1
    		Front view of DLC3



B
CHECK CAN MAIN WIRE FOR DISCONNECTION (Click here)

C
CHECK CAN BUS LINES FOR SHORT CIRCUIT (Click here)
A


3.CHECK FOR SHORT TO B+ IN CAN BUS WIRE


    E175996E02

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D47-6 (CANH) - D47-16 (BAT)
    		Ignition switch off
    		6 kΩ or higher
    D47-14 (CANL) - D47-16 (BAT)
    		Ignition switch off
    		6 kΩ or higher

    Text in Illustration 
    *1
    		Front view of DLC3



NG
CHECK CAN BUS LINE FOR SHORT TO +B (Click here)
OK


4.CHECK CAN BUS LINE FOR SHORT TO GND


    E175996E03

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D47-6 (CANH) - D47-4 (CG)
    		Ignition switch off
    		200 Ω or higher
    D47-14 (CANL) - D47-4 (CG)
    		Ignition switch off
    		200 Ω or higher

    Text in Illustration 
    *1
    		Front view of DLC3



NG
CHECK CAN BUS LINE FOR SHORT TO GND (Click here)
OK

HOW TO PROCEED WITH TROUBLESHOOTING (Click here)  

5.CHECK CAN BUS WIRE (MAIN WIRE FOR DISCONNECTION, CAN BUS LINES FOR SHORT CIRCUIT)

  1. Turn the ignition switch off.



    E175996E01

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    		Proceed to
    D47-6 (CANH) - D47-14 (CANL)
    		Ignition switch off
    		54 to 69 Ω
    		A
    D47-6 (CANH) - D47-14 (CANL)
    		Ignition switch off
    		70 Ω or higher
    		B
    D47-6 (CANH) - D47-14 (CANL)
    		Ignition switch off
    		53 Ω or less
    		C

    Text in Illustration 
    *1
    		Front view of DLC3



B
CHECK CAN MAIN WIRE FOR DISCONNECTION (Click here)

C
CHECK CAN BUS LINES FOR SHORT CIRCUIT (Click here)
A


6.CHECK FOR SHORT TO B+ IN CAN BUS WIRE


    E175996E02

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D47-6 (CANH) - D47-16 (BAT)
    		Ignition switch off
    		6 kΩ or higher
    D47-14 (CANL) - D47-16 (BAT)
    		Ignition switch off
    		6 kΩ or higher

    Text in Illustration 
    *1
    		Front view of DLC3



NG
CHECK CAN BUS LINE FOR SHORT TO +B (Click here)
OK


7.CHECK CAN BUS LINE FOR SHORT TO GND


    E175996E03

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D47-6 (CANH) - D47-4 (CG)
    		Ignition switch off
    		200 Ω or higher
    D47-14 (CANL) - D47-4 (CG)
    		Ignition switch off
    		200 Ω or higher

    Text in Illustration 
    *1
    		Front view of DLC3



NG
CHECK CAN BUS LINE FOR SHORT TO GND (Click here)
OK

HOW TO PROCEED WITH TROUBLESHOOTING (Click here)