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DTC U1002: Lost Communication with Gateway Module [09/2017 - 05/2019]: Procedure

  1. CHECK CAN BUS LINE (MALFUNCTION CONFIRMATION) 
    1. Turn the power switch off.
    2. Disconnect the cable from the negative (-) auxiliary battery terminal.
    3. Measure the resistance according to the value(s) in the table below.
      GTY810297Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Driving Support ECU Assembly)

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      I157-8 (CA1P) - I157-9 (CA1N) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω Below 54 Ω:
      Short circuit between bus lines
      70 Ω or more:
      Open circuit in a main bus line or driving support ECU assembly branch line
      I157-8 (CA1P) - I157-28 (GND) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω:
      CANH ground short
      I157-9 (CA1N) - I157-28 (GND) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω:
      CANH ground short
      I157-8 (CA1P) - I157-7 (B) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ:
      CANH +B short
      I157-9 (CA1N) - I157-7 (B) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ:
      CANH +B short
    4. Connect the cable to the negative (-) auxiliary battery terminal.

      Result

      Result Proceed to
      OK A
      NG (Open circuit in main line or Driving support ECU assembly branch line) B
      NG (Short circuit between main lines) C
      NG (Short to +B or ground) D

    Result: 

    B 

    See step  3

    Result: 

    C 

    See step  8

    Result: 

    D 

    See step  12

    Result: 

    A 

    See step  2

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

      Refer to DTC CHECK / CLEAR [09/2017 - 05/2019]

      Body Electrical > Pre-Collision 2 > Clear DTCs 

    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 [09/2017 - 05/2019]

      Body Electrical > Pre-Collision 2 > Trouble Codes 

      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 [09/2017 - 05/2019] 

    Result: 

    B 

    REPLACE DRIVING SUPPORT ECU ASSEMBLY. Refer to  REMOVAL [09/2017 - 05/2019] 

  3. CHECK FOR OPEN IN CAN BUS BRANCH LINES (DRIVING SUPPORT ECU ASSEMBLY) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the I157 driving support ECU assembly connector.
      GTY812409Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      (to Driving Support ECU Assembly)

      *a Front view of wire harness connector
      (to Driving Support ECU Assembly)
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      I157-8 (CA1P) - I157-9 (CA1N) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

      HINT: 

      If the resistance is between 108 and 132 Ω, there may be an open in a CAN bus main line. If the value is 132 Ω or more, there may be an open in a CAN bus branch line between the No. 9 CAN junction connector and the driving support ECU or a connector may be disconnected.

    4. Connect the I157 driving support ECU assembly connector.
    5. Connect the cable to the negative (-) auxiliary battery terminal.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  7

    Result: 

    OK 

    See step  4

  4. CHECK FOR OPEN IN CAN BUS MAIN LINES (NO. 9 CAN JUNCTION CONNECTOR) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the I163 No. 9 CAN junction connector.
      GTY824397Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to No. 9 CAN Junction Connector)
      *b to Forward Recognition Camera
      *c to Millimeter Wave Radar Sensor Assembly
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Connected to
      I163-3 (CANH) - I163-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Forward Recognition Camera
      I163-1 (CA1P) - I163-12 (CA1N) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Millimeter Wave Radar Sensor Assembly
    4. Connect the I163 No. 9 CAN junction connector.
    5. Connect the cable to the negative (-) auxiliary battery terminal.

      Result

      Result Proceed to
      OK A
      NG (Forward Recognition Camera Main Line) B
      NG (Millimeter Wave Radar Sensor Assembly Main Line) C

    Result: 

    A 

    REPLACE NO. 9 CAN JUNCTION CONNECTOR 

    Result: 

    C 

    See step  6

    Result: 

    B 

    See step  5

  5. CHECK FOR OPEN IN CAN BUS MAIN LINES (FORWARD RECOGNITION CAMERA) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the T18 forward recognition camera connector.
      GTY828239Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Forward Recognition Camera)
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      T18-6 (CANH) - T18-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
    4. Connect the T18 forward recognition camera connector.
    5. Connect the cable to the negative (-) auxiliary battery terminal.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE FORWARD RECOGNITION CAMERA. Refer to  REMOVAL [09/2017 - 05/2019] 

    Result: 

    NG 

    REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 9 CAN JUNCTION CONNECTOR - FORWARD RECOGNITION CAMERA) 

  6. CHECK FOR OPEN IN CAN BUS MAIN LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the B10 millimeter wave radar sensor assembly connector.
      GTY816662Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Millimeter Wave Radar Sensor Assembly)
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      B10-5 (CA1P) - B10-6 (CA1N) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
    4. Connect the B10 millimeter wave radar sensor assembly connector.
    5. Connect the cable to the negative (-) auxiliary battery terminal.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  REMOVAL [09/2017 - 05/2019] 

    Result: 

    NG 

    REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 9 CAN JUNCTION CONNECTOR - MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 

  7. CHECK FOR OPEN IN CAN BUS BRANCH LINES (DRIVING SUPPORT ECU ASSEMBLY) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the I157 driving support ECU assembly connector.
      GTY812409Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Driving Support ECU Assembly)
    3. Disconnect the I163 No. 9 CAN junction connector.
      GTY838093Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to No. 9 CAN Junction Connector)
      *b to Driving Support ECU Assembly
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      I163-2 (CA1P) - I157-8 (CA1P) Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω
      I163-13 (CA1N) - I157-9 (CA1N) Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω
    5. Connect the I163 No. 9 CAN junction connector.
    6. Connect the I157 driving support ECU assembly connector.
    7. Connect the cable to the negative (-) auxiliary battery terminal.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE NO. 9 CAN JUNCTION CONNECTOR 

    Result: 

    NG 

    REPAIR OR REPLACE CAN BUS BRANCH WIRE (NO. 9 CAN JUNCTION CONNECTOR - DRIVING SUPPORT ECU ASSEMBLY) 

  8. CHECK FOR SHORT BETWEEN CAN BUS LINES (FORWARD RECOGNITION CAMERA) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the T18 forward recognition camera connector.
      GTY828239Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Forward Recognition Camera)
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      T18-6 (CANH) - T18-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
    4. Connect the T18 forward recognition camera connector.
    5. Connect the cable to the negative (-) auxiliary battery terminal.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE FORWARD RECOGNITION CAMERA. Refer to  REMOVAL [09/2017 - 05/2019] 

    Result: 

    NG 

    See step  9

  9. CHECK FOR SHORT BETWEEN CAN BUS LINES (NO. 9 CAN JUNCTION CONNECTOR) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the I163 No. 9 CAN junction connector.
      GTY824395Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to No. 9 CAN Junction Connector)
      *b to Forward Recognition Camera
      *c to Millimeter Wave Radar Sensor Assembly
      *d to Driving Support ECU Assembly
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Connected to
      I163-3 (CANH) - I163-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Forward Recognition Camera
      I163-1 (CA1P) - I163-12 (CA1N) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Millimeter Wave Radar Sensor Assembly
      I163-2 (CA1P) - I163-13 (CA1N) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Driving Support ECU Assembly
    4. Connect the I163 No. 9 CAN junction connector.
    5. Connect the cable to the negative (-) auxiliary battery terminal.

      Result

      Result Proceed to
      OK A
      NG (Forward Recognition Camera Main Line) B
      NG (Millimeter Wave Radar Sensor Assembly Main Line) C
      NG (Driving Support ECU Assembly Branch Line) D

    Result: 

    A 

    REPLACE NO. 9 CAN JUNCTION CONNECTOR 

    Result: 

    B 

    REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 9 CAN JUNCTION CONNECTOR - FORWARD RECOGNITION CAMERA) 

    Result: 

    D 

    See step  11

    Result: 

    C 

    See step  10

  10. CHECK FOR SHORT BETWEEN CAN BUS LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the B10 millimeter wave radar sensor assembly connector.
      GTY816662Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Millimeter Wave Radar Sensor Assembly)
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      B10-5 (CA1P) - B10-6 (CA1N) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
    4. Connect the B10 millimeter wave radar sensor assembly connector.
    5. Connect the cable to the negative (-) auxiliary battery terminal.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  REMOVAL [09/2017 - 05/2019] 

    Result: 

    NG 

    REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 9 CAN JUNCTION CONNECTOR - MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 

  11. CHECK FOR SHORT BETWEEN CAN BUS LINES (DRIVING SUPPORT ECU ASSEMBLY) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the I157 driving support ECU assembly connector.
      GTY812409Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Driving Support ECU Assembly)
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      I157-8 (CA1P) - I157-9 (CA1N) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
    4. Connect the I157 driving support ECU assembly connector.
    5. Connect the cable to the negative (-) auxiliary battery terminal.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE DRIVING SUPPORT ECU ASSEMBLY. Refer to  REMOVAL [09/2017 - 05/2019] 

    Result: 

    NG 

    REPAIR OR REPLACE CAN BUS BRANCH LINE OR CONNECTOR (NO. 9 CAN JUNCTION CONNECTOR - DRIVING SUPPORT ECU ASSEMBLY) 

  12. CHECK FOR SHORT IN CAN BUS LINE (FORWARD RECOGNITION CAMERA) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the T18 forward recognition camera connector.
      GTY828239Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Forward Recognition Camera)
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      T18-6 (CANH) - Body ground Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      T18-12 (CANL) - Body ground Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      T18-6 (CANH) - +B Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher
      T18-12 (CANL) - +B Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher
    4. Connect the T18 forward recognition camera connector.
    5. Connect the cable to the negative (-) auxiliary battery terminal.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE FORWARD RECOGNITION CAMERA. Refer to  REMOVAL [09/2017 - 05/2019] 

    Result: 

    NG 

    See step  13

  13. CHECK FOR SHORT IN CAN BUS LINE (NO. 9 CAN JUNCTION CONNECTOR) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the I163 No. 9 CAN junction connector.
      GTY824395Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to No. 9 CAN Junction Connector)
      *b to Forward Recognition Camera
      *c to Millimeter Wave Radar Sensor Assembly
      *d to Driving Support ECU Assembly
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Connected to
      I163-3 (CANH) - Body ground Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Forward Recognition Camera
      I163-14 (CANL) - Body ground
      I163-3 (CANH) - +B 6 kΩ or higher
      I163-14 (CANL) - +B
      I163-1 (CA1P) - Body ground Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Millimeter Wave Radar Sensor Assembly
      I163-12 (CA1N) - Body ground
      I163-1 (CA1P) - +B 6 kΩ or higher
      I163-12 (CA1N) - +B
      I163-2 (CA1P) - Body ground Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Driving Support ECU Assembly
      I163-13 (CA1N) - Body ground
      I163-2 (CA1P) - +B 6 kΩ or higher
      I163-13 (CA1N) - +B
    4. Connect the I163 No. 9 CAN junction connector.
    5. Connect the cable to the negative (-) auxiliary battery terminal.

      Result

      Result Proceed to
      OK A
      NG (Forward Recognition Camera Main Line) B
      NG (Millimeter Wave Radar Sensor Assembly Main Line) C
      NG (Driving Support ECU Assembly Branch Line) D

    Result: 

    A 

    REPLACE NO. 9 CAN JUNCTION CONNECTOR 

    Result: 

    B 

    REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 9 CAN JUNCTION CONNECTOR - FORWARD RECOGNITION CAMERA) 

    Result: 

    D 

    See step  15

    Result: 

    C 

    See step  14

  14. CHECK FOR SHORT IN CAN BUS LINE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the B10 millimeter wave radar sensor assembly connector.
      GTY816662Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Millimeter Wave Radar Sensor Assembly)
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      B10-5 (CA1P) - Body ground Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      B10-6 (CA1N) - Body ground Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      B10-5 (CA1P) - +B Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher
      B10-6 (CA1N) - +B Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher
    4. Connect the B10 millimeter wave radar sensor assembly connector.
    5. Connect the cable to the negative (-) auxiliary battery terminal.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  REMOVAL [09/2017 - 05/2019] 

    Result: 

    NG 

    REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 9 CAN JUNCTION CONNECTOR - MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 

  15. CHECK FOR SHORT IN CAN BUS LINE (DRIVING SUPPORT ECU ASSEMBLY) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the I157 driving support ECU assembly connector.
      GTY812409Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Driving Support ECU Assembly)
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      I157-8 (CA1P) - Body ground Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      I157-9 (CA1N) - Body ground Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      I157-8 (CA1P) - +B Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher
      I157-9 (CA1N) - +B Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher
    4. Connect the I157 driving support ECU assembly connector.
    5. Connect the cable to the negative (-) auxiliary battery terminal.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE DRIVING SUPPORT ECU ASSEMBLY. Refer to  REMOVAL [09/2017 - 05/2019] 

    Result: 

    NG 

    REPAIR OR REPLACE CAN BUS BRANCH LINE OR CONNECTOR (NO. 9 CAN JUNCTION CONNECTOR - DRIVING SUPPORT ECU ASSEMBLY) 

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