How To Proceed With Troubleshooting

Standard voltage: 

11 to 14 V 

HINT:

If the voltage is below 11 V, 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 ignition 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 ignition 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 ignition switch off.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance 

   RESISTANCE SPECIFIED CONDITIONS
   
   

   Tester Connection	Switch Condition	Result	Proceed to
   E15-6 (CANH) - E15-14 (CANL)	Ignition switch off	54 to 69 Ω	A
   E15-6 (CANH) - E15-14 (CANL)	Ignition switch off	70 Ω or higher	B
   E15-6 (CANH) - E15-14 (CANL)	Ignition switch off	Below 54 Ω	C

   Fig 1: Identifying Terminal CANH And CANL Of DLC3 Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   B: GO TO  "OPEN IN CAN MAIN BUS LINE "

   C: GO TO  "CHECK CAN BUS LINES FOR SHORT CIRCUIT "

   A: Go to Next Step 

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

   Standard resistance 

   RESISTANCE SPECIFIED CONDITIONS
   
   

   Tester Connection	Switch Condition	Specified Condition
   E15-6 (CANH) - E15-4 (CG)	Ignition switch off	200 Ω or higher
   E15-14 (CANL) - E15-4 (CG)	Ignition switch off	200 Ω or higher

   Fig 2: Identifying Terminal CANH, CANL And CG Of DLC3 Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: GO TO  "CHECK CAN BUS LINE FOR SHORT TO GND "

   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 SPECIFIED CONDITIONS
   
   

   Tester Connection	Condition	Specified Condition
   E15-6 (CANH) - E15-16 (BAT)	Cable is disconnected from negative battery terminal	6 kΩ or higher
   E15-14 (CANL) - E15-16 (BAT)	Cable is disconnected from negative battery terminal	6 kΩ or higher

   Fig 3: Identifying Terminal CANH, CANL And BAT Of DLC3 Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: GO TO  "CHECK CAN BUS LINE FOR SHORT TO +B "

   OK: Go to Next Step 

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

   Result 

   RESULT CHART
   
   

   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*1
   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
   All ECUs and sensors except the network gateway ECU connected to the CAN No. 2 bus are not displayed on the screen. The network gateway ECU outputs DTC U1002. (Open in CAN No. 2 bus main wire or short in CAN No. 2 bus wire)	D
   All ECUs and sensors connected to the CAN No. 2 bus are not displayed on the screen. (Open in network gateway ECU branch wire or network gateway ECU malfunction)	E

   NOTE:

   • The systems (ECUs, sensors) that adopt CAN communication vary depending on the vehicle and optional equipment. Check which systems (ECUs, sensors) are installed on the vehicle (See DIAGNOSIS SYSTEM  ).
   • Non-installed ECUs or sensors will not be displayed. Do not mistake them for being in the communication stop mode.
   • The ECUs and sensors that repeatedly appear and disappear from the screen during this check are considered normal. (The response to the Techstream display are affected by signals output from other ECUs which have an open circuit in either of their CAN branch wires.)

   HINT:

   • *1: See the DTC Chart instead of Communication Stop mode Table when some of the ECUs connected to the CAN No. 2 bus are not displayed on the screen (See DIAGNOSTIC TROUBLE CODE CHART  ).
   • The ECUs connected to the CAN No. 2 bus are displayed on the screen by the network gateway ECU.

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

   C: GO TO OPEN IN ONE SIDE OF CAN BRANCH WIRE  (See OPEN IN ONE SIDE OF CAN BRANCH LINE  )

   D: GO TO DTC CHART U1002  (See DTC U1002 (CAN NO. 2 BUS) LOST COMMUNICATION WITH GATEWAY MODULE (NETWORK GATEWAY ECU); DTC U0114 LOST COMMUNICATION WITH 4WD CONTROL ECU  )

   E: GO TO NETWORK GATEWAY ECU COMMUNICATION STOP MODE  (See GATEWAY ECU COMMUNICATION STOP MODE  )

   A: Go to Next Step 

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 has been set. Refer to the DTC combination table for the CAN bus.
• The network gateway ECU will store communication error DTCs when the ECUs connected to the CAN No. 2 bus cannot communicate, or if a network malfunction occurs.

  Result 

  RESULT CHART
  
  

  Result	Proceed to
  Communication error DTCs other than the codes output from the network gateway ECU is output. (A malfunction occurred in the CAN No. 1 bus.)	A
  The network gateway ECU outputs DTC U0114 and U1002. (A malfunction occurred in the CAN No. 2 bus.)	B

  B: GO TO DTC CHART U1002  (See DTC U1002 (CAN NO. 2 BUS) LOST COMMUNICATION WITH GATEWAY MODULE (NETWORK GATEWAY ECU); DTC U0114 LOST COMMUNICATION WITH 4WD CONTROL ECU  )

  A: Go to Next Step 

1. Confirm a trouble according to the combination of output DTCs regarding the CAN communication system (See DIAGNOSTIC TROUBLE CODE CHART  ).

   HINT:

   Previous CAN communication system DTCs may be caused if CAN communication system DTCs are output and all ECUs and sensors connected to the CAN communication system are displayed on the Techstream's "CAN Bus Check" screen.