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DTC U1002: Lost Communication with Gateway Module (Main Body) [12/2013 - ]: Procedure

  1. CHECK CAN MS BUS LINES 
    1. Turn the power switch off.
    2. Measure the resistance according to the value(s) in the table below.
      GTY347649Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Switch Condition Specified Condition Result
      H100-1 (CANH) - H100-2 (CANL) Power switch off 54 to 69 Ω Below 54 Ω:
      Short circuit between bus lines
      70 Ω or more:
      Open circuit in a main bus line
      H100-1 (CANH) - H44-4 (CG) Power switch off 200 Ω or higher Below 200 Ω:
      CANH ground short
      H100-2 (CANL) - H44-4 (CG) Power switch off 200 Ω or higher Below 200 Ω:
      CANL ground short
    3. Disconnect the cable from the negative (-) battery terminal.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      H100-1 (CANH) - H44-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ:
      CANH +B short
      H100-2 (CANL) - H44-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ:
      CANL +B short
      TEXT IN ILLUSTRATION

      *1 DLC3
      *a Component with harness connected
      (CAN No. 6 Junction Connector)

      Result

      Result Proceed to
      OK A
      Open circuit in CAN main bus line B
      Short circuit between bus lines C
      • Ground short
      • +B short
      		 D

    B → See step   3 

    C → See step   5 

    D → See step   9 

    A: Go to next step 

  2. RECONFIRM DTC OUTPUT (MAIN BODY ECU) 
    1. Clear the DTCs.
    2. Turn the power switch off.
    3. Turn the power switch on (IG) and recheck for DTCs.

      Result

      Result Proceed to
      U1002 is output from main body ECU A
      Other DTC is output B

    B → GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC 

    A → See step   13 

  3. CHECK FOR OPEN IN CAN MS BUS MAIN LINE (CAN NO. 6 J/C - MAIN BODY ECU) 
    1. Disconnect the main body ECU main line harness connector from the CAN No. 6 junction connector.
      GTY350165Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      H100-1 (CANH) - H100-2 (CANL) Power switch off 108 to 132 Ω
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to CAN No. 6 Junction Connector)

    NG → See step   4 

    OK → REPLACE CAN NO. 6 JUNCTION CONNECTOR 

  4. CHECK FOR OPEN IN CAN MS BUS MAIN LINES (MAIN BODY ECU) 
    1. Reconnect the main body ECU main line harness connector to the CAN No. 6 junction connector.
    2. Disconnect the main body ECU connector.
      GTY354826Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      H17-9 (CANP) - H17-10 (CANN) Power switch off 108 to 132 Ω
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to Main Body ECU (Multiplex Network Body ECU))

    NG → REPAIR OR REPLACE CAN MS BUS MAIN LINE OR CONNECTOR (CAN NO. 6 J/C - MAIN BODY ECU) 

    OK → See step   13 

  5. CHECK FOR SHORT IN CAN MS BUS LINES (CAN NO. 6 J/C - MAIN BODY ECU) 
    1. Disconnect the main body ECU main line harness connector from the CAN No. 6 junction connector.
      GTY350165Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      H100-1 (CANH) - H100-2 (CANL) Power switch off 108 to 132 Ω
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to CAN No. 6 Junction Connector)

    NG → See step   8 

    OK: Go to next step 

  6. CHECK FOR SHORT IN CAN MS BUS LINES (CAN NO. 6 J/C) 
    1. Reconnect the main body ECU main line harness connector to the CAN No. 6 junction connector.
      GTY354044Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Component with harness connected
      (CAN No. 6 Junction Connector)
    2. Connect the probes of an ohmmeter to terminals 1 (CANH) and 2 (CANL) of the main body ECU main line harness connector.
    3. While observing the resistance value shown on the ohmmeter, disconnect branch line connectors (except H100) from the CAN No. 6 junction connector until the resistance becomes normal (between 54 and 69 Ω).
      GTY354185Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 CAN No. 6 Junction Connector - -
      *a Junction Connector B Side *b Junction Connector A Side
      *c Earth Terminal *d Front view of wire harness connector
      (to CAN No. 6 Junction Connector)
      JUNCTION CONNECTOR A SIDE

      Terminal No. (Symbol) Wiring Color Connected to
      H103-1 (GND) W-B Body ground
      H99-1 (CANH) R Outer mirror control ECU assembly (Front passenger side)
      H99-2 (CANL) W
      H100-1 (CANH) G Main body ECU
      (Multiplex network body ECU)
      H100-2 (CANL) W
      H101-1 (CANH) L Position control ECU and switch assembly
      H101-2 (CANL) W
      H102-1 (CANH) Y Outer mirror control ECU assembly
      (Driver side)
      H102-2 (CANL) W

      Result

      Result Proceed to
      The resistance is still below 54 Ω when all the specified connectors are disconnected.
      (There is no short in the branch lines.)      		 A
      The resistance becomes normal (between 54 and 69 Ω) when a connector is disconnected.
      (There is a short in the branch lines.)      		 B

    B → See step   7 

    A → REPLACE CAN NO. 6 JUNCTION CONNECTOR 

  7. CHECK FOR SHORT IN CAN MS BUS LINES (ECU) 
    1. Reconnect the connector for the short-circuited branch line to the CAN junction connector (the connector that caused the bus line resistance to become normal (between 54 and 69 Ω) when it was disconnected).
    2. Disconnect the connector that includes terminals CANH and CANL from the ECU to which the short-circuited branch line is connected.
    3. Measure the resistance according to the value(s) in the table below.
      GTY354044Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      H100-1 (CANH) - H100-2 (CANL) Power switch off 54 to 69 Ω
      TEXT IN ILLUSTRATION

      *a Component with harness connected
      (CAN No. 6 Junction Connector)

      HINT: 

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

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

    OK → REPLACE CORRESPONDING ECU OR SWITCH 

  8. CHECK FOR SHORT IN CAN MS BUS LINES (MAIN BODY ECU) 
    1. Reconnect the main body ECU main line harness connector to the CAN No. 6 junction connector.
    2. Disconnect the main body ECU connector.
      GTY354826Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      H17-9 (CANP) - H17-10 (CANN) Power switch off 108 to 132 Ω
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to Main Body ECU (Multiplex Network Body ECU))

    NG → REPAIR OR REPLACE CAN MS BUS MAIN LINE OR CONNECTOR (CAN NO. 6 J/C - MAIN BODY ECU) 

    OK → See step   13 

  9. CHECK FOR SHORT IN CAN MS BUS LINE (CAN NO. 6 J/C - MAIN BODY ECU) 
    1. Disconnect the main body ECU main line harness connector from the CAN No. 6 junction connector.
      GTY359230Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      INSPECTION FOR CAN GROUND SHORT

      Tester Connection Switch Condition Specified Condition
      H100-1 (CANH) - H44-4 (CG) Power switch off 200 Ω or higher
      H100-2 (CANL) - H44-4 (CG) Power switch off 200 Ω or higher
      INSPECTION FOR CAN +B SHORT

      Tester Connection Condition Specified Condition
      H100-1 (CANH) - H44-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      H100-2 (CANL) - H44-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      TEXT IN ILLUSTRATION

      *1 DLC3
      *a Rear view of wire harness connector
      (to CAN No. 6 Junction Connector)

      HINT: 

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN MS Bus Line inspection.

    NG → See step   12 

    OK: Go to next step 

  10. CHECK FOR SHORT IN CAN MS BUS LINE (CAN NO. 6 J/C) 
    1. Reconnect the main body ECU main line harness connector to the CAN No. 6 junction connector.
      GTY355797Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 DLC3
      *a Component with harness connected
      (CAN No. 6 Junction Connector)
    2. Connect the probes of an ohmmeter to terminals 1 (CANH) and 2 (CANL) of the main body ECU main line harness connector and CG or BAT of the DLC3.

      HINT: 

      It is only necessary to perform the inspection for the result (short circuit) that was obtained in the Check CAN MS Bus Line inspection.

    3. While observing the resistance value shown on the ohmmeter, disconnect branch line connector (except H100) from the CAN No. 6 junction connector until the resistance becomes normal (6 kΩ or higher (for +B short) or 200 Ω or higher (for ground short)).
      GTY354185Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 CAN No. 6 Junction Connector - -
      *a Junction Connector B Side *b Junction Connector A Side
      *c Earth Terminal *d Front view of wire harness connector
      (to CAN No. 6 Junction Connector)
      JUNCTION CONNECTOR A SIDE

      Terminal No. (Symbol) Wiring Color Connected to
      H103-1 (GND) W-B Body ground
      H99-1 (CANH) R Outer mirror control ECU assembly
      (Front passenger side)
      H99-2 (CANL) W
      H100-1 (CANH) G Main body ECU
      (Multiplex network body ECU)
      H100-2 (CANL) W
      H101-1 (CANH) L Position control ECU and switch assembly
      H101-2 (CANL) W
      H102-1 (CANH) Y Outer mirror control ECU assembly
      (Driver side)
      H102-2 (CANL) W

      Result

      Result Proceed to
      The resistance between terminals CANP and BAT, or the resistance between terminals CANN and BAT is still below 6 kΩ when all the specified connectors are disconnected from the CAN junction connector.
      (There is no short to +B in the branch lines.)      		 A
      The resistance between terminals CANP and GND, or the resistance between terminals CANN and GND is still below 200 Ω when all the specified connectors are disconnected from the CAN junction connector.
      (There is no short to GND in the branch lines.)
      The resistance between terminals CANP and BAT, or the resistance between terminals CANN and BAT becomes normal (6 kΩ or higher) when a connector is disconnected from the CAN junction connector.
      (There is a short to +B in one of the areas related to one or more of the disconnected branch lines.)      		 B
      The resistance between terminals CANP and GND, or the resistance between terminals CANN and GND becomes normal (200 Ω or higher) when a connector is disconnected from the CAN junction connector.
      There is a short to GND in one of the areas related to one or more of the disconnected branch lines.)

    B → See step   11 

    A → REPLACE CAN NO. 6 JUNCTION CONNECTOR 

  11. CHECK FOR SHORT IN CAN MS BUS LINE (ECU) 
    1. Reconnect the connector for the bus line that is shorted to +B or GND to the CAN junction connector (the connector that caused the bus line resistance to change to 6 kΩ or higher (for +B short) or 200 Ω or higher (for ground short) when it was disconnected).
    2. Disconnect the connector that includes terminals CANH and CANL from the ECU to which the bus line shorted to +B or GND is connected.
    3. Measure the resistance according to the value(s) in the table below.
      GTY355797Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT: 

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN MS Bus Line inspection.

      Standard Resistance

      INSPECTION FOR CAN GROUND SHORT

      Tester Connection Switch Condition Specified Condition
      H100-1 (CANH) - H44-4 (CG) Power switch off 200 Ω or higher
      H100-2 (CANL) - H44-4 (CG) Power switch off 200 Ω or higher
      INSPECTION FOR CAN +B SHORT

      Tester Connection Condition Specified Condition
      H100-1 (CANH) - H44-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      H100-2 (CANL) - H44-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      TEXT IN ILLUSTRATION

      *1 DLC3
      *a Component with harness connected
      (CAN No. 6 Junction Connector)

      HINT: 

      If the resistance becomes normal when the connector is disconnected from the ECU, there may be a short in the ECU.

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

    OK → REPLACE CORRESPONDING ECU OR SWITCH 

  12. CHECK FOR SHORT IN CAN MS BUS LINE (MAIN BODY ECU) 
    1. Disconnect the main body ECU connector.
    2. Measure the resistance according to the value(s) in the table below.
      GTY359230Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      INSPECTION FOR CAN GROUND SHORT

      Tester Connection Switch Condition Specified Condition
      H100-1 (CANH) - H44-4 (CG) Power switch off 200 Ω or higher
      H100-2 (CANL) - H44-4 (CG) Power switch off 200 Ω or higher
      INSPECTION FOR CAN +B SHORT

      Tester Connection Condition Specified Condition
      H100-1 (CANH) - H44-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      H100-2 (CANL) - H44-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      HINT: 

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN MS Bus Line inspection.

      TEXT IN ILLUSTRATION

      *1 DLC3
      *a Rear view of wire harness connector
      (to CAN No. 6 Junction Connector)

    NG → REPAIR OR REPLACE CAN MS BUS MAIN LINE OR CONNECTOR (CAN NO. 6 J/C - MAIN BODY ECU) 

    OK → See step   13 

  13. REPLACE MULTIPLEX NETWORK BODY ECU (MAIN BODY ECU). Refer to  REMOVAL [12/2013 - ] 
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