CAN COMMUNICATION SYSTEM(w/ Central Gateway ECU) Check Bus 5 Line for Short to GND

DESCRIPTION

There may be a short circuit between one of the CAN bus lines and GND when there is no resistance between terminal 15 (CA5H) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3, or terminal 16 (CA5L) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3.

Symptom Trouble Area
There is no resistance between terminal 15 (CA5H) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3, or terminal 16 (CA5L) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3.

  • Short to ground in CAN main bus line

  • Short to ground in CAN branch line

  • 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 TO GND IN CAN BUS LINE (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.

      B005ZHGC02
      *1 DLC3 - -
      *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) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Millimeter wave radar sensor assembly*1
      L203-2 (CANL) - L61-4 (CG)
      L199-1 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Central gateway ECU (network gateway ECU)
      L199-2 (CANL) - L61-4 (CG)
      L198-1 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Central gateway ECU (network gateway ECU)
      L198-2 (CANL) - L61-4 (CG)
      L185-1 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Forward recognition camera*1
      L185-2 (CANL) - L61-4 (CG)
      L184-1 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Hybrid vehicle control ECU
      L184-2 (CANL) - L61-4 (CG)
      L183-1 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Parking assist ECU*2
      L183-2 (CANL) - L61-4 (CG)
      L182-1 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Driving support ECU assembly*1
      L182-2 (CANL) - L61-4 (CG)

      • *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 TO GND IN CAN BUS LINE (ECU OR SENSOR) Click here

    B

  2. CHECK FOR SHORT TO GND IN CAN BUS LINE (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) - NO. 4 CAN JUNCTION CONNECTOR)


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

    2. B005YK8C98
      *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) - L192-10 (GND) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      L192-16 (CA5L) - L192-10 (GND)
      L192-9 (CAXH) - L192-10 (GND) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      L192-24 (CAXL) - L192-10 (GND)

    OK

    REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) Click here

    NG

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

  3. CHECK FOR SHORT TO GND IN CAN BUS LINE (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 bus line shorted to GND is connected Click here.

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

      B005YEPC87
      *1 DLC3 - -
      *a

      Component with harness connected

      (Central Gateway ECU (Network Gateway ECU))

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      L192-15 (CA5H) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      L192-16 (CA5L) - L61-4 (CG)

      Tech Tips


      • If the resistance changes to 200 Ω or higher 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 to ground 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