CAN COMMUNICATION SYSTEM(w/ Central Gateway ECU) Check Bus 5 Lines for Short Circuit

DESCRIPTION

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

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

  • Short in CAN main bus lines

  • Short in CAN branch lines

  • Central gateway ECU (network gateway ECU)

  • Hybrid vehicle control ECU

  • Driving support ECU assembly

    (w/ Toyota Safety Sense)

  • Forward recognition camera

    (w/ Toyota Safety Sense)

  • Parking assist ECU

    (w/ Intelligent Parking Assist System)

  • Millimeter wave radar sensor assembly

    (w/ Toyota Safety Sense)

  • No. 4 CAN junction connector

WIRING DIAGRAM

B005ZHLE01

CAUTION / NOTICE / HINT

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

Note


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

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work Click here.

  • 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.

  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

    DTC check procedure: Turn the power switch on (IG) and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.

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

Tech Tips


  • Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.

  • When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.

  • Connectors that connect to the CAN junction connector can be distinguished by the color of their CAN bus lines. When the connectors have been disconnected from the CAN junction connector, reconnecting the connectors to non-original positions on the CAN junction connector does not affect system performance. However, it is preferred to reconnect the connectors to their original positions to avoid negative effects on the wiring such as tension on the wire harnesses, and to make future maintenance easier.

PROCEDURE


  1. CHECK FOR SHORT IN CAN BUS LINES (NO. 4 CAN JUNCTION CONNECTOR)


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

    2. Disconnect the L182, L183, L184, L185, L198, L199 and L203 No. 4 CAN junction connectors.

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

      B005XKYC01
      *a

      Rear view of wire harness connector

      (to No. 4 CAN Junction Connector)

      		 *b

      to Millimeter Wave Radar Sensor Assembly

      (w/ Toyota Safety Sense)
      *c to Central Gateway ECU (Network Gateway ECU) *d

      to Forward Recognition Camera

      (w/ Toyota Safety Sense)
      *e to Hybrid Vehicle Control ECU *f

      to Parking assist ECU

      (w/ Intelligent Parking Assist System)
      *g

      to Driving Support ECU Assembly

      (w/ Toyota Safety Sense)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      L203-1 (CANH) - L203-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Millimeter wave radar sensor assembly*1
      L199-1 (CANH) - L199-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Central gateway ECU (network gateway ECU)
      L198-1 (CANH) - L198-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Central gateway ECU (network gateway ECU)
      L185-1 (CANH) - L185-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Forward recognition camera*1
      L184-1 (CANH) - L184-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Hybrid vehicle control ECU
      L183-1 (CANH) - L183-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Parking assist ECU*2
      L182-1 (CANH) - L182-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Driving support ECU assembly*1

      • *1: w/ Toyota Safety Sense

      • *2: w/ Intelligent Parking Assist System

      Result
      Result Proceed to
      OK A
      NG (Line to central gateway ECU (network gateway ECU)) B
      NG (Line to ECU or sensor) C

    A

    REPLACE NO. 4 CAN JUNCTION CONNECTOR

    C

    CHECK FOR SHORT IN CAN BUS LINES (ECU OR SENSOR) Click here

    B

  2. CHECK FOR SHORT IN CAN BUS LINES (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))


    1. Disconnect the L192 central gateway ECU (network gateway ECU) connector.

    2. B005YK8C96
      *a

      Front view of wire harness connector

      (to Central Gateway ECU (Network Gateway ECU))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L192-15 (CA5H) - L192-9 (CAXH) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher
      L192-16 (CA5L) - L192-24 (CAXL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher

    OK

    REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (CENTRAL GATEWAY ECU - NO. 4 CAN JUNCTION CONNECTOR)

  3. CHECK FOR SHORT IN CAN BUS LINES (ECU OR SENSOR)


    1. Reconnect all wire harness connectors.

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

    3. B005XN1C52
      *a

      Component with harness connected

      (Central Gateway ECU (Network Gateway ECU))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L192-15 (CA5H) - L192-16 (CA5L) Cable disconnected from negative (-) auxiliary 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.

      • If the resistance does not become normal when the connector is disconnected from the ECU or sensor, check for a short in the wire harness and repair or replace the wire harness or connector if necessary.


    OK

    REPLACE ECU OR SENSOR

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR