How To Proceed With Troubleshooting

Standard voltage: 

11 to 14 V 

HINT.

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

HINT.

• CAN communication DTCs are output when there is an open or short in any of the communication wires Any problems with the power source of a corresponding ECU or sensor, or problems in the ECU, the sensor itself also cause these DTCs to be output.
• If a CAN communication wire connector is disconnected with the engine switch on (IG), the ECUs of the corresponding system and related systems record a DTC.

1. Based on the vehicle equipment and specifications, confirm the systems that use CAN communication (See DIAGNOSIS SYSTEM  ).

HINT:

Operating the engine switch, any other switches, or a door triggers related ECU and sensor communication on the CAN This communication will cause the resistance value to change

1. Turn the engine switch off.
2. Measure the resistance according to the value(s) in the table below

   Standard Resistance 

   RESISTANCE REFERENCE
   
   

   Tester Connection	Condition	Specified Value	Proceed to
   J21-6(CANH) - J21-14(CANL)	Engine switch off	54 to 69 Ω	A
   J21-6(CANH) - J21-14(CANL)	Engine switch off	70 Ω or higher	B
   J21-6(CANH) - J21-14(CANL)	Engine switch off	Below 54 Ω	C

   Fig 1: Identifying DLC3 And J21 Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

B: GO TO " OPEN IN CAN MAIN WIRE  " . 

C: GO TO " SHORT IN CAN BUS LINES  " . 

A: Go to Next Step 

1. Turn the engine switch off.
2. Measure the resistance according to the value(s) in the table below

   Standard Resistance 

   RESISTANCE REFERENCE
   
   

   Tester Connection	Condition	Specified Value
   J21-6(CANH) - J21-4 (CG)	Engine switch off	200 Ω or more
   J21-14(CANL) - J21-4 (CG)	Engine switch off	200 Ω or more

Fig 2: Identifying DLC3 And J21 Connector Terminal
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: GO TO " SHORT TO GND IN CAN BUS LINE  " . 

OK: Go to Next Step 

1. Disconnect the negative battery terminal
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance 

   RESISTANCE REFERENCE
   
   

   Tester Connection	Condition	Specified Value
   J21-6(CANH) - J21-16 (BAT)	Cable from negative battery terminal disconnected	6 kΩ or more
   J21-14(CANL) - J21-16 (BAT)	Cable from negative battery terminal disconnected	6 kΩ or more

Fig 3: Identifying DLC3 And J21 Connector Terminal
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: GO TO " SHORT TO +B IN CAN BUS LINE  " . 

OK: Go to Next Step 

1. Check which of the following is adopted: dynamic radar / laser cruise control and vehicle stability control

1. Using the Techstream, select "CAN Bus Check" from the "System Select".
2. Observe the screen for approximately 1 minute to check the ECUs and sensors displayed on the screen.

   Result 

   DTC RESULT REFERENCE
   
   

   Result	Proceed to
   All ECUs and sensors connected to the CAN communication system are displayed on the screen. (CAN bus circuit is currently normal)	A
   One of the ECUs and sensors connected to the CAN communication system is not displayed on the screen. (Open in ECU or sensor branch wires, or communication interrupted)	B
   Some ECUs and sensors repeatedly appear and disappear from the screen during this check. (Open in one side of ECU or sensor branch wires)	C

   NOTE:

   • The systems (ECUs, sensors) that adopt CAN communication vary depending on the vehicle and option settings. Check which systems (ECUs, sensors) are installed on the vehicle.
   • Non-installed ECUs or sensors are not displayed. Do not mistake them for being in the communication stop mode.
   • Techstream display is affected by signals output from other ECUs which have an open circuit in either of their CAN branch wires.

B: GO TO "COMMUNICATION STOP MODE TABLE"  (See PROBLEM SYMPTOMS TABLE  ).

C: GO TO " OPEN IN ONE SIDE OF CAN BRANCH LINE  " . 

A: Go to Next Step 

1. Confirm trouble according to the combination of output DTCs regarding the CAN communication system (See DIAGNOSIS SYSTEM  )

   HINT.

   • Sometimes CAN communication system DTCs are output, but all the ECUs and sensors connected to the CAN communication system are displayed on the Techstream In this case, previous or history DTCs may indicate the cause of the problem.
   • ECUs related to a problem in the CAN bus will store DTCs to indicate communication malfunctions. The communication stop mode in the CAN bus can be determined by comparing the combination of DTCs that have been set Refer to the DTC COMBINATION TABLE  for the CAN bus.

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