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DTC U1002: Lost Communication with Gateway Module [08/2019 - ]: Procedure

  1. CHECK CAN BUS LINE (MALFUNCTION CONFIRMATION) 
    1. Turn the engine switch off.
    2. Disconnect the cable from the negative (-) battery terminal.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      A66-5 (CA1P) - A66-6 (CA1N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω Below 54 Ω:
      Short circuit between CAN bus lines
      70 Ω or more:
      Open circuit in a CAN bus line
      A66-5 (CA1P) - A66-1 (SGND) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω:
      Ground short
      A66-6 (CA1N) - A66-1 (SGND) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω:
      Ground short
      A66-5 (CA1P) - A66-8 (IGB) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ:
      +B short
      A66-6 (CA1N) - A66-8 (IGB) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ:
      +B short
      GTY742412Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Millimeter Wave Radar Sensor Assembly)

      Result

      Result Proceed to
      OK A
      NG (Open circuit in CAN bus line) B
      NG (Short circuit between CAN bus lines) C
      NG (Short to +B or ground) D

    Result: 

    B 

    See step  3

    Result: 

    C 

    See step  5

    Result: 

    D 

    See step  7

    Result: 

    A 

    See step  2

  2. CHECK FOR DTCs (PRE-COLLISION SYSTEM) 
    1. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [08/2019 - ]

    2. Make sure that the DTC detection conditions are met.

      HINT: 

      If the detection conditions are not met, the system cannot detect the malfunction.

    3. Check for DTCs.

      Refer to DTC CHECK / CLEAR [08/2019 - ]

      Result

      Result Proceed to
      DTC U1002 is not output A
      DTC U1002 is output B

    Result: 

    A 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2019 - ] 

    Result: 

    B 

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  REMOVAL [08/2017 - ] 

  3. CHECK FOR OPEN IN CAN BUS LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - FORWARD RECOGNITION CAMERA) 
    1. Disconnect the U22 forward recognition camera connector.
    2. Disconnect the A66 millimeter wave radar sensor assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      U22-6 (CANH) - A66-5 (CA1P) Cable disconnected from negative (-) battery terminal Below 1 Ω
      U22-12 (CANL) - A66-6 (CA1N) Cable disconnected from negative (-) battery terminal Below 1 Ω
    4. Connect the A66 millimeter wave radar sensor assembly connector.
    5. Connect the U22 forward recognition camera connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE CAN BUS LINE OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - FORWARD RECOGNITION CAMERA) 

    Result: 

    OK 

    See step  4

  4. CHECK FOR OPEN IN CAN BUS LINES (FORWARD RECOGNITION CAMERA) 
    1. Disconnect the U22 forward recognition camera connector.
      GTY747075Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Forward Recognition Camera)
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      U22-6 (CANH) - U22-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
    3. Connect the U22 forward recognition camera connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE FORWARD RECOGNITION CAMERA. Refer to  REMOVAL [08/2017 - ] 

    Result: 

    NG 

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  REMOVAL [08/2017 - ] 

  5. CHECK FOR SHORT BETWEEN CAN BUS LINES (FORWARD RECOGNITION CAMERA) 
    1. Disconnect the U22 forward recognition camera connector.
      GTY747075Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Forward Recognition Camera)
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      U22-6 (CANH) - U22-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
    3. Connect the U22 forward recognition camera connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE FORWARD RECOGNITION CAMERA. Refer to  REMOVAL [08/2017 - ] 

    Result: 

    NG 

    See step  6

  6. CHECK FOR SHORT BETWEEN CAN BUS LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 
    1. Disconnect the A66 millimeter wave radar sensor assembly connector.
      GTY765430Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Millimeter Wave Radar Sensor Assembly)
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A66-5 (CA1P) - A66-6 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
    3. Connect the A66 millimeter wave radar sensor assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  REMOVAL [08/2017 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE CAN BUS LINE OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 

  7. CHECK FOR SHORT IN CAN BUS LINE (FORWARD RECOGNITION CAMERA) 
    1. Disconnect the U22 forward recognition camera connector.
      GTY1027410Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 DLC3 - -
      *a Front view of wire harness connector
      (to Forward Recognition Camera)      		 - -
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      U22-6 (CANH) - H218-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      U22-12 (CANL) - H218-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      U22-6 (CANH) - H218-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      U22-12 (CANL) - H218-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
    3. Connect the U22 forward recognition camera connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE FORWARD RECOGNITION CAMERA. Refer to  REMOVAL [08/2017 - ] 

    Result: 

    NG 

    See step  8

  8. CHECK FOR SHORT IN CAN BUS LINE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 
    1. Disconnect the A66 millimeter wave radar sensor assembly connector.
      GTY1027401Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 DLC3 - -
      *a Front view of wire harness connector
      (to Millimeter Wave Radar Sensor Assembly)      		 - -
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A66-5 (CA1P) - H218-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      A66-6 (CA1N) - H218-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      A66-5 (CA1P) - H218-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      A66-6 (CA1N) - H218-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
    3. Connect the A66 millimeter wave radar sensor assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  REMOVAL [08/2017 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE CAN BUS LINE OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 

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