How To Proceed With Troubleshooting

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

HINT: 

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

1. VEHICLE BROUGHT TO WORKSHOP 

   NEXT: Go to next step 

2. INSPECT BATTERY VOLTAGE 

   Standard voltage

   11 to 14 V

   If the voltage is below 11 V, recharge or replace the battery before proceeding.

   NEXT: Go to next step 

3. CHECK AND CLEAR DTC* 
   1. Using the Techstream, perform the Health Check (all DTCs check).
      NOTE:

      • If there is a CAN communication trouble code that indicates that an ECU or sensor has a power malfunction or interior malfunction which is causing a communication stop, the problem may not be in the communication line.
      • When CAN communication related connectors are disconnected with the ignition switch ON or ACC, the ECU related to the connector and ECUs of related systems will store a CAN communication DTC.

      NEXT: Go to next step 

4. CHECK INSTALLED SYSTEMS (ECU AND SENSOR) THAT USE CAN COMMUNICATION 
   1. Based on the vehicle equipment and specifications, confirm the systems that use CAN communication. Refer to DIAGNOSIS SYSTEM .

      NEXT: Go to next step 

5. CHECK DLC3 BRANCH WIRE AND V BUS CIRCUIT MAIN WIRE (CANH - CANL) 
   1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the main wire and the branch wire.
   2. Measure the resistance according to the value(s) in the table below.
      Fig 1: Checking DLC3 Branch Wire And V Bus Circuit Main Wire (CANH - CANL)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection	Switch Condition	Specified Condition	Proceed to
      6 (CANH) - 14 (CANL)	Ignition switch off	OK (54 to 69 Ω)	A
      6 (CANH) - 14 (CANL)	Ignition switch off	NG (70 Ω or higher)	B
      6 (CANH) - 14 (CANL)	Ignition switch off	NG (Below 54 Ω)	C

      TEXT IN ILLUSTRATION
      
      

      *a	Front view of DLC3

      B → Go to OPEN IN CAN MAIN BUS LINE. Refer to  Open in CAN Main Bus Line  

      C → Go to CHECK CAN BUS LINES FOR SHORT CIRCUIT. Refer to  Check CAN Bus Lines for Short Circuit  

      A: Go to next step 

6. CHECK V BUS CIRCUIT +B (CANH, CANL - BAT) 
   1. Measure the resistance according to the value(s) in the table below.
      Fig 2: Checking V Bus Circuit +B (CANH, CANL - BAT)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

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

      TEXT IN ILLUSTRATION
      
      

      *a	Front view of DLC3

      RESULT
      
      

      Result	Proceed to
      OK	A
      NG	B

      B → Go to CHECK CAN BUS LINE FOR SHORT TO +B. Refer to  Check CAN Bus Line for Short to +B  

      A: Go to next step 

7. CHECK V BUS CIRCUIT GND (CANH, CANL - CG) 
   1. Measure the resistance according to the value(s) in the table below.
      Fig 3: Checking V BUS Circuit GND (CANH, CANL - CG)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

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

      TEXT IN ILLUSTRATION
      
      

      *a	Front view of DLC3

      RESULT
      
      

      Result	Proceed to
      OK	A
      NG	B

      B → Go to CHECK CAN BUS LINE FOR SHORT TO GND. Refer to  Check CAN Bus Line for Short to GND  

      A: Go to next step 

8. CHECK ECUS CONNECTED TO CAN BUS* 
   1. Connect the cable to the negative (-) battery terminal.
   2. Select "CAN Bus Check" from "System Select".
   3. Wait 1 minute and then check the display of the connected ECUs and sensors.
      RESULT
      
      

      Inspection Result	Proceed to
      All ECUs and sensors connected to the CAN communication system are displayed on the screen.	A
      One ECU or sensor connected to the CAN communication system are displayed on the screen.	B
      2 or more ECUs and sensors connected to the CAN communication system are displayed on the screen.	C

      NOTE:

      The ECUs and sensors that are not present will not be displayed. Be careful not to mistake them for communication stop malfunctions.

      HINT: 

      If the display of an ECU is intermittent during the check, one side of an ECU or sensor branch wire is open (The signal of the ECU is treated as noise, which affects the response and display of the Techstream).

      B → Go to PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE  

      C → Go to OPEN IN ONE SIDE OF CAN BRANCH LINE. Refer to  Open in One Side of CAN Branch Line  

      A: Go to next step 

9. CHECK COMMUNICATION MALFUNCTION DTC (PAST DTC CHECK)* 
   1. Select "CAN Bus Check" from "System Select".
   2. Write down all of the DTCs stored in each ECU.

      HINT: 

      • If there are communication malfunction DTCs stored but the Techstream "CAN Bus Check - Communication Bus Check" screen displays all of the ECUs and sensors connected to the CAN system, the communication malfunction DTCs may be past malfunctions that are no longer present.
      • For V bus main wire malfunctions, related ECUs are also detected. Therefore, determine the malfunctioning area based on all of the DTCs that are output.

      NEXT: Go to next step 

10. CHECK DTC COMBINATION TABLE (V BUS CIRCUIT BRANCH WIRE OPEN PAST MALFUNCTION) 
    1. Based on the combination of stored CAN communication system DTCs, determine which ECUs and sensors have a communication stop malfunction. Refer to DIAGNOSIS SYSTEM .

       NEXT: Go to next step 

11. PERFORM MALFUNCTION SIMULATION TEST (V BUS CIRCUIT MAIN WIRE PAST MALFUNCTION)* 
    1. Using the Techstream, clear all DTCs.
    2. Perform a malfunction simulation test on all harnesses and connectors related to the V bus circuit main wire.
    3. Check the DTCs that were stored as a result of the malfunction simulation test. Then determine the malfunctioning area.

       NEXT: Go to next step 

12. ADJUST, REPAIR AND REPLACE 

    NEXT: Go to next step 

13. CONFIRMATION TEST 

    NEXT → END