CAN COMMUNICATION SYSTEM(for LHD with Central Gateway ECU) Check Bus 5 Lines for Short Circuit

DESCRIPTION

There may be a short circuit between the bus 5 CAN main wires and/or CAN branch wires when the resistance between terminals 15 (CA5H) and 16 (CA5L) of the central gateway ECU is below 54 Ω.

Detection Item Trouble Area
Resistance between terminals 15 (CA5H) and 16 (CA5L) of central gateway ECU is below 54 Ω.

  • Short in bus 5 CAN main wires

  • Short in bus 5 CAN branch wires

  • Central gateway ECU

  • Driving support ECU assembly*1

  • Millimeter wave radar sensor assembly*1

  • Forward recognition camera*1

  • Inner rear view mirror assembly*2, *7

  • Blind spot monitor sensor LH*3

  • Clearance warning ECU assembly*4

  • Parking assist ECU*5

  • Suspension control ECU*6

  • No. 3 CAN junction connector

  • No. 4 CAN junction connector

  • No. 1 CAN junction terminal

WIRING DIAGRAM

A01XB4KE08
A01WZWQE01

CAUTION / NOTICE / HINT

Note


  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output Click here.

  • Before measuring the resistance of the CAN bus, turn the ignition switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • 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.

  • After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed Click here.

Tech Tips


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

  • Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE


  1. CHECK FOR SHORT IN CAN BUS WIRES (CENTRAL GATEWAY ECU - NO. 3 CAN JUNCTION CONNECTOR)


    1. Disconnect the cable from the negative (-) battery terminal.

    2. A01XAAQE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Central Gateway ECU)

      Disconnect the central gateway ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E145-15 (CA5H) - E145-16 (CA5L) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    OK

    REPLACE CENTRAL GATEWAY ECU Click here

    NG

  2. CONNECT CONNECTOR


    1. Reconnect the E145 central gateway ECU connector.


    NEXT

  3. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 CAN JUNCTION TERMINAL - NO. 4 CAN JUNCTION CONNECTOR)


    1. A01X5LJE02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to No. 1 CAN Junction Terminal)

      Disconnect the No. 1 CAN junction terminal connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K50-3 (CANH) - K50-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    OK

    REPLACE NO. 1 CAN JUNCTION TERMINAL

    NG

  4. CONNECT CONNECTOR


    1. Reconnect the K50 No. 1 CAN junction terminal connector.


    NEXT

  5. CHECK FOR SHORT IN CAN BUS WIRES (NO. 3 CAN JUNCTION CONNECTOR)


    1. Disconnect the No. 3 CAN junction connector.

      A01X4B1E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to No. 3 CAN Junction Connector)

      		 *b to No. 4 CAN Junction Connector
      *c to Driving Support ECU Assembly (w/ Pre-crash Safety System) *d to Central Gateway ECU
      *e to Millimeter Wave Radar Sensor Assembly (w/ Pre-crash Safety System) *f to Clearance Warning ECU Assembly (w/ TOYOTA Parking Assist-sensor System)
      *g to Parking Assist ECU (w/ Multi-terrain Monitor System) *h

      • to Forward Recognition Camera (w/ Pre-crash Safety System)

      • to Inner Rear View Mirror Assembly (w/o Pre-crash Safety System, w/ Automatic High Beam System)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connect to
      E151-3 (CANH) - E151-13 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 4 CAN junction connector
      E151-4 (CANH) - E151-14 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Driving support ECU assembly*1
      E151-5 (CANH) - E151-15 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Central gateway ECU
      E151-6 (CANH) - E151-16 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Millimeter wave radar sensor assembly*1
      E151-7 (CANH) - E151-17 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Clearance warning ECU assembly*3
      E151-8 (CANH) - E151-18 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Parking assist ECU*4
      E151-9 (CANH) - E151-19 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      • Forward recognition camera*1

      • Inner rear view mirror assembly*2, *5

      • *1: w/ Pre-crash Safety System

      • *2: w/o Pre-crash Safety System

      • *3: w/ TOYOTA Parking Assist-sensor System

      • *4: w/ Multi-terrain Monitor System

      • *5: w/ Automatic High Beam System

      Result
      Result Proceed to
      OK A
      NG (Central gateway ECU CAN main wire) B
      NG (No. 4 CAN junction connector CAN main wire) C
      NG (ECU or sensor CAN branch wires) D

    A

    REPLACE NO. 3 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 3 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU)

    D

    CHECK FOR SHORT IN CAN BUS WIRES (ECU, SENSOR) Click here

    C

  6. CONNECT CONNECTOR


    1. Reconnect the E151 No. 3 CAN junction connector.


    NEXT

  7. CHECK FOR SHORT IN CAN BUS WIRES (NO. 4 CAN JUNCTION CONNECTOR)


    1. Disconnect the No. 4 CAN junction connectors.

      A01X8KKE01
      Text in Illustration
      *1 No. 4 CAN Junction Connector - -
      *a

      Rear view of wire harness connector

      (to No. 4 CAN Junction Connector)

      		 - -
      Code Color (CANH Side) Color (CANL Side) Connect to
      K56 W B No. 3 CAN Junction Connector
      K57 SB B No. 1 CAN Junction Terminal
      K58 R B Blind Spot Monitor Sensor LH*1
      K65 L B Suspension Control ECU*2

      • *1: w/ Blind Spot Monitor System

      • *2: w/ Active Height Control System

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K56-1 (CANH) - K56-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      K57-1 (CANH) - K57-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      K58-1 (CANH) - K58-2 (CANL)*1 Cable disconnected from negative (-) battery terminal 200 Ω or higher
      K65-1 (CANH) - K65-2 (CANL)*2 Cable disconnected from negative (-) battery terminal 200 Ω or higher

      • *1: w/ Blind Spot Monitor System

      • *2: w/ Active Height Control System

      Result
      Result Proceed to
      OK A
      NG (No. 3 CAN junction connector CAN main wire) B
      NG (No. 1 CAN junction terminal CAN main wire) C
      NG (ECU or sensor CAN branch wires) D

    A

    REPLACE NO. 4 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 4 CAN JUNCTION CONNECTOR - NO. 3 CAN JUNCTION CONNECTOR)

    C

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 4 CAN JUNCTION CONNECTOR - NO. 1 CAN JUNCTION TERMINAL)

    D

  8. CHECK FOR SHORT IN CAN BUS WIRES (ECU, SENSOR)


    1. A01X25DE02
      Text in Illustration
      *a

      Component with harness connected

      (Central Gateway ECU)

      Reconnect the CAN junction connector.

    2. Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the short circuited CAN branch wire is connected.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E145-15 (CA5H) - E145-16 (CA5L) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

      Tech Tips

      If the resistance becomes normal (between 54 and 69 Ω) when the connector is disconnected from the ECU or sensor, there may be a short in the ECU or sensor.


    OK

    REPLACE CORRESPONDING ECU OR SENSOR

    NG

    REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR CAN BRANCH WIRES OR CONNECTOR