CAN COMMUNICATION SYSTEM(w/o Central Gateway ECU), Diagnostic DTC:U1002

DTC Code DTC Name
U1002 Lost Communication with Gateway Module (Power Management1)

DESCRIPTION


DTC No. DTC Detection Condition Trouble Area
U1002 Power management control ECU cannot receive signals from all ECUs that have been memorized as those connected to sub bus 11.
  • Open or short in sub bus 11 main line or connector

  • Open or short in sub bus 11 branch line or connector

  • Power management control ECU

  • Driving support ECU assembly*1

  • Parking assist ECU*2

  • Lane departure warning camera*3

  • CAN No. 4 junction connector

  • CAN No. 1 junction terminal

*1: w/ Pre-crash Safety System

*2: w/ Intelligent Parking Assist System

*3: w/ Lane Departure Alert System

Tech Tips

This diagnosis procedure is for when DTC U1002 is output by the power management control ECU (GTS display: PM1 Gateway).

WIRING DIAGRAM

A005EULE02

CAUTION / NOTICE / HINT

Note


  • Before measuring the resistance of the CAN bus, turn the power switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work Click here.

  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output Click here.

  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

  • DTC check procedure: Turn the power switch on (IG), wait at least 20 seconds, and then drive the vehicle at a speed of 50 km/h (31 mph) or more at least 1.72 seconds.

  • After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed Click here.

Tech Tips


  • Operating the power switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.

  • Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

  • Connectors that connect to the CAN junction connector can be distinguished by the color of their CAN bus lines. When the connectors have been disconnected from the CAN junction connector, 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.

PROCEDURE


  1. CHECK SUB BUS 11


    1. Disconnect the cable from the negative (-) auxiliary battery terminal.

    2. A0059TBE03
      Text in Illustration
      *a

      Component with harness connected

      (Power Management Control ECU)

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      L5-34 (CA2H) - L5-35 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω Below 54 Ω: Short circuit between bus lines
      70 Ω or higher: Open circuit in main bus lines
      L5-34 (CA2H) - L5-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANH ground short
      L5-35 (CA2L) - L5-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANL ground short
      L5-34 (CA2H) - L5-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANH +B short
      L5-35 (CA2L) - L5-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANL +B short
      Result
      Result Proceed to
      OK A
      NG (Open circuit in CAN main bus line) B
      NG (Short circuit between bus lines) C

      • NG (Ground short)

      • NG (+B short)

      D

    B
    C
    D
    A
  2. CHECK FOR DTC OUTPUT


    1. Reconnect the cable to the negative (-) auxiliary battery terminal.

    2. Connect the GTS to the DLC3.

    3. Turn the power switch on (IG).

    4. Turn the GTS on.

    5. Clear the DTCs.

    6. Turn the power switch off.

    7. Turn the power switch on (IG).

    8. Check for DTCs.

      Result
      Result Proceed to
      DTC U1002 is output from the power management control ECU (GTS display: PM1 Gateway) A
      DTC U1002 is not output from the power management control ECU (GTS display: PM1 Gateway) B

    A
    B
  3. CHECK FOR OPEN IN SUB BUS 11 MAIN LINES (POWER MANAGEMENT CONTROL ECU)


    1. A005CD8E03
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Disconnect the L5 power management control ECU connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      L5-34 (CA2H) - L5-35 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    OK
    NG
  4. CHECK CHECK FOR OPEN IN SUB BUS 11 MAIN LINES (CAN NO. 1 JUNCTION TERMINAL)


    1. Reconnect the L5 power management control ECU connector.

    2. A005AI3E02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN No. 1 Junction Terminal)

      Disconnect the L180 CAN No. 1 junction terminal.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L180-3 (CANH) - L180-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    OK
    NG
  5. CHECK FOR OPEN IN SUB BUS 11 MAIN LINES (CAN NO. 4 JUNCTION CONNECTOR)


    1. Reconnect the L180 CAN No. 1 junction terminal.

    2. A005EG9E02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN No. 4 Junction Connector)

      *b to Power Management Control ECU
      *c to CAN No. 1 Junction Terminal

      Disconnect the L181 and L184 CAN No. 4 junction connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      L184-1 (CANH) - L184-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Power management control ECU
      L181-1 (CANH) - L181-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω CAN No. 1 junction terminal
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connected to
      L184 B G Power management control ECU
      L181 B Y CAN No. 1 junction terminal

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

      Result
      Result Proceed to
      OK A
      NG (Power management control ECU main line) B
      NG (CAN No. 1 junction terminal main line) C

    A
    B
    C
  6. CHECK FOR SHORT IN SUB BUS 11 LINES (POWER MANAGEMENT CONTROL ECU)


    1. A005ATVE03
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Disconnect the L5 power management control ECU connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      L5-34 (CA2H) - L5-35 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    OK
    NG
  7. CHECK FOR SHORT IN SUB BUS 11 LINES (POWER MANAGEMENT CONTROL ECU - CAN NO. 4 JUNCTION CONNECTOR)


    1. Reconnect the L5 power management control ECU connector.

    2. A005D5DE02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN No. 4 Junction Connector)

      *b to Power Management Control ECU

      Disconnect the L184 CAN No. 4 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      L184-1 (CANH) - L184-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Power management control ECU
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connected to
      L184 B G Power management control ECU

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.


    NG
    OK
  8. CHECK FOR SHORT IN SUB BUS 11 LINES (BRANCH LINE)


    1. Reconnect the L184 CAN No. 4 junction connector.

    2. A005CQBE02
      Text in Illustration
      *a

      Component with harness connector

      (CAN No. 4 Junction Connector)

      Connect the probes of an ohmmeter to terminals 1 (CANH) and 2 (CANL) of the power management control ECU main line harness connector.

    3. While observing the resistance value shown on the ohmmeter, disconnect branch line connectors (L182, L183 and L185) from the CAN No. 4 junction connector until the resistance becomes normal (between 54 and 69 Ω).

      A005DV9E05
      Text in Illustration
      *a CAN No. 4 Junction Connector - -
      Wiring Color
      CAN No. 4 Junction Connector Side Code Color (CANH Side) Color (CANL Side)
      CAN main bus line (bus line connecting CAN No. 4 junction connector and CAN No. 1 junction terminal) L181 B Y
      Driving support ECU assembly*1 L182 B R
      Parking assist ECU*2 L183 B L
      CAN main bus line (bus line connecting power management control ECU and CAN No. 1 junction terminal) L184 B G
      Lane departure warning camera*3 L185 B W

      • *1: w/ Pre-crash Safety System

      • *2: w/ Intelligent Parking Assist System

      • *3: w/ Lane Departure Alert System

      CAUTION:

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

      Result
      Result Proceed to

      The resistance is still below 54 Ω when all the specified connectors are disconnected.

      (There are no shorts between a pair of branch lines.)

      A

      The resistance becomes normal (between 54 and 69 Ω) when a connector is disconnected.

      (There is a short between one or more pairs of branch lines.)

      B
    4. When there is a short in one or more of the branch lines:


      1. Reconnect all of the connectors to the CAN junction connector, except for the one that was disconnected last (the short-circuited bus line). Check that the resistance shown on the tester is normal (between 54 and 69 Ω) to confirm that there is a short in the one branch line only.

        Tech Tips


        • 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 wire such as tension on the wire harnesses, and to make future maintenance easier.


    B
    A
  9. CHECK FOR SHORT IN SUB BUS 11 LINES (CAN NO. 4 JUNCTION CONNECTOR)


    1. Disconnect the L181 CAN No. 4 junction connector.

    2. A005EH3E02
      Text in Illustration
      *a

      Component with harness connector

      (CAN No. 4 Junction Connector)

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      L184-1 (CANH) - L184-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.


    NG
    OK
  10. CHECK FOR SHORT IN SUB BUS 11 LINES (CAN NO. 1 JUNCTION TERMINAL)


    1. Reconnect the L181 CAN No. 4 junction connector.

    2. A005AI3E02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN No. 1 Junction Terminal)

      Disconnect the L180 CAN No. 1 junction terminal.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L180-3 (CANH) - L180-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    OK
    NG
  11. CHECK FOR SHORT IN SUB BUS 11 LINES (ECU, SENSOR)


    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 Click here.

    3. A005E83E03
      Text in Illustration
      *a

      Component with harness connector

      (Power Management Control ECU)

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      L5-34 (CA2H) - L5-35 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

      Tech Tips

      If the resistance changes to normal when the connector is disconnected from the ECU or sensor, there may be a short in the ECU or sensor.


    OK
    NG
  12. CHECK FOR SHORT IN SUB BUS 11 BUS LINE (POWER MANAGEMENT CONTROL ECU)


    1. A005B8AE03
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Disconnect the L5 power management control ECU connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      L5-34 (CA2H) - L5-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANH ground short
      L5-35 (CA2L) - L5-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANL ground short
      L5-34 (CA2H) - L5-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANH +B short
      L5-35 (CA2L) - L5-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANL +B short

      Tech Tips

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 11 inspection.

      Find the necessary inspection from the Result column that matches the result in the Result column from the Check Sub Bus 11 inspection.


    OK
    NG
  13. CHECK FOR SHORT IN SUB BUS 11 LINE (CAN NO. 4 JUNCTION CONNECTOR - POWER MANAGEMENT CONTROL ECU)


    1. A005D5DE02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN No. 4 Junction Connector)

      *b to Power Management Control ECU

      Disconnect the L184 CAN No. 4 junction connector.

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

    2. A005ABTE04
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      L5-34 (CA2H) - L5-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANH ground short
      L5-35 (CA2L) - L5-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANL ground short
      L5-34 (CA2H) - L5-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANH +B short
      L5-35 (CA2L) - L5-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANL +B short

      Tech Tips

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 11 inspection.

      Find the necessary inspection from the Result column that matches the result in the Result column from the Check Sub Bus 11 inspection.


    NG
    OK
  14. CHECK FOR SHORT IN SUB BUS 11 LINE (BRANCH LINE)


    1. Reconnect the L184 CAN No. 4 junction connector.

    2. A005ABTE04
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Connect the probes of an ohmmeter to terminals CANH or CANL and GND (E1) or +B (AM22) of the power management control ECU.

      Tech Tips


      • It is only necessary to perform the inspection for the result (short circuit) that was obtained in the Check Sub Bus 11 Line inspection.

      • Find the necessary inspection from the Result column that matches the result in the Result column from the Check Sub Bus 11 inspection.

    3. While observing the resistance value shown on the ohmmeter, disconnect branch line connectors (L182, L183 and L185) from the CAN No. 4 junction connector until the resistance becomes normal (6 kΩ or higher (for +B short) or 200 Ω or higher (for ground short)).

      A005DV9E05
      Text in Illustration
      *a CAN No. 4 Junction Connector - -
      Wiring Color
      CAN No. 4 Junction Connector Side Code Color (CANH Side) Color (CANL Side)
      CAN main bus line (bus line connecting CAN No. 4 junction connector and CAN No. 1 junction terminal) L181 B Y
      Driving support ECU assembly*1 L182 B R
      Parking assist ECU*2 L183 B L
      CAN main bus line (bus line connecting power management control ECU and CAN No. 1 junction terminal) L184 B G
      Lane departure warning camera*3 L185 B W

      • *1: w/ Pre-crash Safety System

      • *2: w/ Intelligent Parking Assist System

      • *3: w/ Lane Departure Alert System

      Result
      Result Proceed to

      The resistance between terminals CANH and +B, or the resistance between terminals CANL and +B 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 CANH and GND, or the resistance between terminals CANL 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 CANH and +B, or the resistance between terminals CANL and +B 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 CANH and GND, or the resistance between terminals CANL 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
    A
  15. CHECK FOR SHORT IN SUB BUS 11 LINE (CAN NO. 4 JUNCTION CONNECTOR)


    1. Disconnect the L181 CAN No. 4 junction connector.

    2. A005ABTE04
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      L5-34 (CA2H) - L5-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANH ground short
      L5-35 (CA2L) - L5-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANL ground short
      L5-34 (CA2H) - L5-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANH +B short
      L5-35 (CA2L) - L5-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANL +B short

      Tech Tips

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 11 inspection.

      Find the necessary inspection from the Result column that matches the result in the Result column from the Check Sub Bus 11 inspection.


    NG
    OK
  16. CHECK FOR SHORT IN SUB BUS 11 LINE (CAN NO. 1 JUNCTION TERMINAL)


    1. Reconnect the L181 CAN No. 4 junction connector.

    2. Disconnect the L180 CAN No. 1 junction terminal.

    3. A005ABTE04
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      L5-34 (CA2H) - L5-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANH ground short
      L5-35 (CA2L) - L5-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANL ground short
      L5-34 (CA2H) - L5-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANH +B short
      L5-35 (CA2L) - L5-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANL +B short

      Tech Tips

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 11 inspection.

      Find the necessary inspection from the Result column that matches the result in the Result column from the Check Sub Bus 11 inspection.


    OK
    NG
  17. CHECK FOR SHORT IN SUB BUS 11 LINE (ECU, SENSOR)


    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 Click here.

    3. A005ABTE04
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      L5-34 (CA2H) - L5-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANH ground short
      L5-35 (CA2L) - L5-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANL ground short
      L5-34 (CA2H) - L5-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANH +B short
      L5-35 (CA2L) - L5-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANL +B short

      Tech Tips

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 11 inspection.

      Find the necessary inspection from the Result column that matches the result in the Result column from the Check Sub Bus 11 inspection.


    OK
    NG