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Home >> Toyota >> 2017 >> Camry LE >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Can Communication System (Diagnostic Codes (U0104-U1002) & Symptom Tests) (Except Hybrid) >> Can Communication System >> Symptom Tests >> Check CAN Bus Line for Short to GND [08/2015 - ] >> Procedure

Check CAN Bus Line for Short to GND [08/2015 - ]: Procedure

  1. CHECK FOR SHORT TO GND IN CAN BUS LINE (DLC3 BRANCH LINE) 
    1. Disconnect the cable from the negative (-) battery terminal.
    2. Disconnect the I96 DLC3 branch line connector from the CAN No. 1 junction connector.
      GTY315478Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to CAN No. 1 Junction Connector)
      *b to DLC3
      NOTE:
      • Before disconnecting the connector, make a note of where it is connected.
      • Reconnect the connector to its original position.
    3. Measure the resistance according to the value(s) in the table below.
      GTY314988Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Condition Specified Condition
      I39-6 (CANH) - I39-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      I39-14 (CANL) - I39-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      TEXT IN ILLUSTRATION

      *1 DLC3

    NG → REPAIR OR REPLACE CAN BRANCH LINE CONNECTED TO DLC3 

    OK: Go to next step 

  2. CHECK FOR SHORT TO GND IN CAN BUS LINE 
    1. Reconnect the I96 DLC3 branch line connector to the CAN No. 1 junction connector.
    2. Disconnect the connectors from the CAN No. 1 junction connector or CAN No. 2 junction connector one at a time.

      HINT: 

      Disconnect the ECU and sensor connectors other than the DLC3 branch lines and CAN main bus lines between the CAN No. 1 junction connector and CAN No. 2 junction connector.

      GTY314988Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 DLC3
    3. Using an ohmmeter, measure the resistance between terminals 6 (CANH) and 4 (CG), and between terminals 14 (CANL) and 4 (CG) of the DLC3 each time a connector is disconnected.
      GTY477124Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *A w/ Intuitive Parking Assist System *B for Tire Pressure Warning System with Tire Inflation Pressure Display Function
      *C w/ Smart Key System *D w/ Network Gateway ECU
      *E for Navigation Receiver Type *F for Radio and Display Type
      *G for 2AR-FE *H for 2GR-FE
      *1 Clearance Warning ECU Assembly *2 Tire Pressure Warning ECU and Receiver
      *3 Air Conditioning Amplifier Assembly *4 ECM
      *5 Brake Actuator Assembly (Skid Control ECU) *6 Smart Key ECU Assembly (Certification ECU)
      *7 Network Gateway ECU *8 Navigation Receiver Assembly
      *9 Radio and Display Receiver Assembly *10 Combination Meter Assembly
      *11 Power Steering ECU with Motor Assembly *12 Power Steering ECU Assembly
      *13 DLC3 *14 Airbag Sensor Assembly
      *15 Steering Sensor *16 Main Body ECU (Multiplex Network Body ECU)
      *17 CAN No. 2 Junction Connector *18 CAN No. 1 Junction Connector
      GTY383195Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Component without harness connected
      (CAN No. 1 Junction Connector)      		 - -
      WIRING COLOR

      CAN No. 1 Junction Connector Side Code Color (CANH Side) Color (CANL Side)
      Main body ECU (Multiplex network body ECU) I95 P W
      Steering sensor I97 V W
      Airbag sensor assembly I103 Y W
      DLC3 I96 L W
      • Power steering ECU with motor assembly*1
      • Power steering ECU assembly*2
      		 I100 G W
      Combination meter assembly I94 R W
      CAN main bus line (bus line connecting CAN No. 1 junction connector and CAN No. 2 junction connector) I93 B W
      • *1: for 2AR-FE
      • *2: for 2GR-FE
      GTY545628Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Component without harness connected
      (CAN No. 2 Junction Connector)      		 - -
      WIRING COLOR

      CAN No. 2 Junction Connector Side Code Color (CANH Side) Color (CANL Side)
      CAN main bus line (bus line connecting CAN No. 1 junction connector and CAN No. 2 junction connector) I101 B W
      • Navigation receiver assembly*1
      • Radio and display receiver assembly*2
      		 I107 R W
      Network gateway ECU*3 I108 G W
      Smart key ECU assembly (Certification ECU)*4 I106 L W
      Brake actuator assembly (Skid control ECU) I105 Y W
      Air conditioning amplifier assembly I102 V W
      ECM I104 P W
      • Clearance warning ECU assembly*5
      • Tire pressure warning ECU and receiver*6
      		 I111*5
      I191*6      		 BE W
      • *1: for Navigation Receiver Type
      • *2: for Radio and Display Type
      • *3: w/ Network Gateway ECU
      • *4: w/ Smart Key System
      • *5: w/ Intuitive Parking Assist System
      • *6: for Tire Pressure Warning System with Tire Inflation Pressure Display Function
      NOTE:

      Do not reconnect the disconnected connectors until this inspection is complete because there may be a short to GND in 2 or more CAN bus lines.

      Result

      Symptom Proceed to
      The resistance between terminals 6 (CANH) and 4 (CG), or the resistance between 14 (CANL) and 4 (CG) is still below 200 Ω when all the specified connectors are disconnected from the CAN junction connector. (There is a short to GND in the CAN main bus lines between the CAN No. 1 junction connector and CAN No. 2 junction connector.) A
      The resistance between terminals 6 (CANH) and 4 (CG), or the resistance between 14 (CANL) and 4 (CG) becomes normal (200 Ω or more) when a connector is disconnected from the CAN junction connector. (There is a short to GND in one of the areas that relate to one or more of the disconnected bus lines.) B
    4. When there is a short to GND in one or more of the bus lines that connect to an ECU or sensor:
      1. Reconnect all of the connectors to the CAN junction connector, except for the one that was disconnected last (the bus line that is shorted to GND). Check that the resistance shown on the tester is normal (200 Ω or more) to confirm that there is a short to GND in the one bus line only.

        HINT: 

        • Connectors that connect to the CAN junction connector can be distinguished by the color of their CAN bus lines.
        • 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.
    5. When there is no short to GND in any of the bus lines that connect to the ECUs and sensors:
      1. With all the specified connectors for ECUs and sensors disconnected, proceed with the inspection of the CAN bus main lines between the CAN No. 1 junction connector and CAN No. 2 junction connector.

    B → See step   5 

    A: Go to next step 

  3. CHECK CAN NO. 1 JUNCTION CONNECTOR 
    1. Disconnect the I93 CAN main bus line connector from the CAN No. 1 junction connector.
      GTY321052Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to CAN No. 1 Junction Connector)
      *b (to CAN No. 2 Junction Connector)
      NOTE:
      • Before disconnecting the connector, make a note of where it is connected.
      • Reconnect the connector to its original position.
    2. Measure the resistance according to the value(s) in the table below.
      GTY314988Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Condition Specified Condition
      I39-6 (CANH) - I39-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      I39-14 (CANL) - I39-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      TEXT IN ILLUSTRATION

      *1 DLC3

    NG → REPLACE CAN NO. 1 JUNCTION CONNECTOR 

    OK: Go to next step 

  4. CHECK CAN NO. 2 JUNCTION CONNECTOR (CAN NO. 1 J/C - CAN NO. 2 J/C) 
    1. Reconnect the I93 CAN main bus line connector to the CAN No. 1 junction connector.
    2. Disconnect the I101 CAN main bus line connector from the CAN No. 2 junction connector.
      GTY316421Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to CAN No. 2 Junction Connector)
      *b (to CAN No. 1 Junction Connector)
      NOTE:
      • Before disconnecting the connector, make a note of where it is connected.
      • Reconnect the connector to its original position.
    3. Measure the resistance according to the value(s) in the table below.
      GTY314988Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Condition Specified Condition
      I39-6 (CANH) - I39-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      I39-14 (CANL) - I39-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      TEXT IN ILLUSTRATION

      *1 DLC3

    NG → REPAIR OR REPLACE CAN BUS MAIN LINE (CAN NO. 1 JUNCTION CONNECTOR - CAN NO. 2 JUNCTION CONNECTOR) 

    OK → REPLACE CAN NO. 2 JUNCTION CONNECTOR 

  5. CHECK FOR SHORT TO GND IN CAN BUS LINE (ECU, SENSOR) 
    1. Reconnect the connector of the bus line that is shorted to GND to the CAN junction connector (the connector that caused the bus line resistance to change to 200 Ω or more when it was disconnected).
    2. Disconnect the connector that includes the DLC3 connected CAN lines (such as CANH and CANL) from the ECU or sensor to which the bus line shorted to GND is connected. Refer to TERMINALS OF ECU [08/2015 - ] .
      GTY314988Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 DLC3
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      I39-6 (CANH) - I39-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      I39-14 (CANL) - I39-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      HINT: 

      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.

    NG → REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR BUS LINE OR CONNECTOR 

    OK → REPLACE CORRESPONDING ECU OR SENSOR 

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