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DTC U1002: Lost Communication with Gateway Module [08/2019 - 08/2021]: Procedure

  1. CHECK CAN BUS LINE (MALFUNCTION CONFIRMATION) 
    1. Turn the ignition 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
      k1-5 (CA1P) - k1-6 (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
      k1-5 (CA1P) - k1-1 (SGND) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω:
      Ground short
      k1-6 (CA1N) - k1-1 (SGND) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω:
      Ground short
      k1-5 (CA1P) - k1-8 (IGB) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ:
      +B short
      k1-6 (CA1N) - k1-8 (IGB) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ:
      +B short
      GTY844690Courtesy 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  6

    Result: 

    D 

    See step  9

    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 [08/2019 - 08/2021] 

  3. CHECK FOR OPEN IN CAN BUS LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - FORWARD RECOGNITION CAMERA) 
    1. Disconnect the S12 forward recognition camera connector.
    2. Disconnect the k1 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
      S12-6 (CANH) - k1-5 (CA1P) Cable disconnected from negative (-) battery terminal Below 1 Ω
      S12-12 (CANL) - k1-6 (CA1N) Cable disconnected from negative (-) battery terminal Below 1 Ω
    4. Connect the k1 millimeter wave radar sensor assembly connector.
    5. Connect the S12 forward recognition camera connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  5

    Result: 

    OK 

    See step  4

  4. CHECK FOR OPEN IN CAN BUS LINES (FORWARD RECOGNITION CAMERA) 
    1. Disconnect the S12 forward recognition camera connector.
      GTY861581Courtesy 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
      S12-6 (CANH) - S12-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
    3. Connect the S12 forward recognition camera connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE FORWARD RECOGNITION CAMERA. Refer to  REMOVAL [08/2019 - ] 

    Result: 

    NG 

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  REMOVAL [08/2019 - 08/2021] 

  5. CHECK MILLIMETER WAVE RADAR WIRE 
    1. Disconnect the k1 millimeter wave radar sensor assembly connector.
    2. Disconnect the Ak1 millimeter wave radar wire connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      Ak1-5 - k1-5 (CA1P) Always Below 1 Ω
      Ak1-6 - k1-6 (CA1N) Always Below 1 Ω
    4. Connect the k1 millimeter wave radar assembly connector.
    5. Connect the Ak1 millimeter wave radar sensor wire connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

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

    Result: 

    NG 

    REPAIR MILLIMETER WAVE RADAR WIRE. Refer to  REMOVAL [08/2019 - 08/2021] 

  6. CHECK FOR SHORT BETWEEN CAN BUS LINES (FORWARD RECOGNITION CAMERA) 
    1. Disconnect the S12 forward recognition camera connector.
      GTY931337Courtesy 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
      S12-6 (CANH) - S12-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
    3. Connect the S12 forward recognition camera connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE FORWARD RECOGNITION CAMERA. Refer to  REMOVAL [08/2019 - ] 

    Result: 

    NG 

    See step  7

  7. CHECK FOR SHORT BETWEEN CAN BUS LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 
    1. Disconnect the k1 millimeter wave radar sensor assembly connector.
      GTY916185Courtesy 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
      k1-5 (CA1P) - k1-6 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
    3. Connect the k1 millimeter wave radar sensor assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  REMOVAL [08/2019 - 08/2021] 

    Result: 

    NG 

    See step  8

  8. CHECK MILLIMETER WAVE RADAR WIRE 
    1. Disconnect the Ak1 millimeter wave radar wire connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      Ak1-5 (CA1P) - Ak1-6 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      GTY882123Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Millimeter Wave Radar Wire)
    3. Connect the Ak1 millimeter wave radar sensor wire connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPAIR MILLIMETER WAVE RADAR WIRE. Refer to  REMOVAL [08/2019 - 08/2021] 

    Result: 

    NG 

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

  9. CHECK FOR SHORT IN CAN BUS LINE (FORWARD RECOGNITION CAMERA) 
    1. Disconnect the S12 forward recognition camera connector.
      GTY918217Courtesy 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
      S12-6 (CANH) - F103-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      S12-12 (CANL) - F103-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      S12-6 (CANH) - F103-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      S12-12 (CANL) - F103-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
    3. Connect the S12 forward recognition camera connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE FORWARD RECOGNITION CAMERA. Refer to  REMOVAL [08/2019 - ] 

    Result: 

    NG 

    See step  10

  10. CHECK FOR SHORT IN CAN BUS LINE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 
    1. Disconnect the k1 millimeter wave radar sensor assembly connector.
      GTY921935Courtesy 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
      k1-5 (CA1P) - F103-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      k1-6 (CA1N) - F103-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      k1-5 (CA1P) - F103-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      k1-6 (CA1N) - F103-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
    3. Connect the k1 millimeter wave radar sensor assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  REMOVAL [08/2019 - 08/2021] 

    Result: 

    NG 

    See step  11

  11. CHECK FOR SHORT IN CAN BUS LINE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 
    1. Disconnect the Ak1 millimeter wave radar wire connector.
      GTY921934Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 DLC3 - -
      *a Front view of wire harness connector
      (to Millimeter Wave Radar Wire)      		 - -
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      Ak1-5 - F103-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      Ak1-6 - F103-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      Ak1-5 - F103-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      Ak1-6 - F103-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
    3. Connect the Ak1 millimeter wave radar wire connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPAIR MILLIMETER WAVE RADAR WIRE. Refer to  REMOVAL [08/2019 - 08/2021] 

    Result: 

    NG 

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

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