CAN COMMUNICATION SYSTEM, Diagnostic DTC:U1002

DTC Code DTC Name
U1002 Lost Communication with Gateway Module (Power Management2)

DESCRIPTION

  • The power management control ECU stores this DTC when no signals can be received from the ECUs that have been memorized as those connected to the sub bus 12.

  • When the power management control ECU receives a response signal from the ECUs connected to the sub bus 12, the power management ECU recognizes and memorizes that the ECU is connected to the sub bus 12. Based on this memorized data, the power management control ECU monitors for malfunctions in the ECUs connected to the sub bus 12 when communicating with those ECUs. If the power management control ECU cannot receive response signals from the ECUs that have been memorized as those connected to the sub bus 12, the power management control ECU determines that a malfunction exists.

  • If 2 or more DTCs are output during the DTC check, one side of the CAN branch wire may be open (one side of the CANH [CAN branch wire]/CANL [CAN branch wire] of the ECU and/or sensor is open).

DTC Code

DTC Detection Condition

Trouble Area

U1002

Lost communication with the gateway module (Power Management2).

  • Sub bus 12 circuit

  • Air conditioning amplifier assembly CAN branch wire or connector*

  • Power management control ECU CAN main wire or connector

  • ECM CAN main wire or connector

  • Air conditioning amplifier assembly*

  • Power management control ECU

  • ECM

  • No. 5 CAN junction connector*

  • For vehicles with a 1WW engine type.

  • *: w/ Entry and Start System

WIRING DIAGRAM

C352029E01

CAUTION / NOTICE / HINT

Note:

  • 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).

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

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

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

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

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

Tip:

  • Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • 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.

PROCEDURE

  1. CHECK VEHICLE CONDITION

    1. Check the vehicle condition.

      Table 1. Result

      Result

      Proceed to

      w/ Entry and Start System

      A

      w/o Entry and Start System

      B

    CHECK FOR OPEN IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU CAN MAIN WIRE)Click here

  2. CHECK SUB BUS 12

    1. U122875E02

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

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      Resistance: Malfunction

      H71-12 (CA3P) - H71-11 (CA3N)

      Cable disconnected from negative (-) battery terminal

      54 to 69 Ω

      Below 53 Ω: Short in line

      H71-12 (CA3P) - H71-11 (CA3N)

      Higher than 70 Ω: Open in CAN main bus line

      H71-12 (CA3P) - H71-1 (AM22)

      Cable disconnected from negative (-) battery terminal

      6 kΩ or higher

      Below 6 kΩ: +B short

      H71-11 (CA3N) - H71-1 (AM22)

      H71-12 (CA3P) - H71-6 (GND)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      Below 200 Ω: Ground short

      H71-11 (CA3N) - H71-6 (GND)
      Table 2. Text in Illustration

      *a

      Component with harness connected

      (to Power Management Control ECU)
      Table 3. Result

      Result

      Proceed to

      OK

      A

      NG (Open circuit in CAN main bus wire)

      B

      NG (Short circuit between bus wires)

      C

      NG

      • +B short

      • Ground short

      D

    CHECK FOR OPEN IN CAN BUS WIRE (NO. 5 CAN JUNCTION CONNECTOR)Click here

    CHECK FOR SHORT IN CAN BUS WIRES (NO. 5 CAN JUNCTION CONNECTOR)Click here

    CHECK FOR SHORT IN CAN BUS WIRES (NO. 5 CAN JUNCTION CONNECTOR)Click here

  3. CHECK FOR DTC

    1. Clear the DTCs.

    2. Recheck for DTCs and check that no DTCs are output.

      OK

      DTC U1002 is not output.

      Table 4. Result

      Result

      Proceed to

      OK

      A

      NG (for LHD)

      B

      NG (for RHD)

      C

    USE SIMULATION METHOD TO CHECK

    (Click here)

    REPLACE POWER MANAGEMENT CONTROL ECU

    (Click here)

    REPLACE POWER MANAGEMENT CONTROL ECU

    (Click here)

  4. CHECK FOR OPEN IN CAN BUS WIRE (NO. 5 CAN JUNCTION CONNECTOR)

    U184762E02

    1. Disconnect the No. 5 CAN junction connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      Connected to

      H126-5 (CANH) - H126-16 (CANL)

      Cable disconnected from negative (-) battery terminal

      108 to 132 Ω

      ECM

      H126-6 (CANH) - H126-17 (CANL)

      Cable disconnected from negative (-) battery terminal

      108 to 132 Ω

      Power management control ECU
      Table 5. Text in Illustration

      *a

      Rear view of wire harness connector

      (to No. 5 CAN Junction Connector)

      *b

      to ECM

      *c

      to Power Management Control ECU
      Table 6. Result

      Result

      Proceed to

      OK

      A

      NG (to ECM CAN main wire)

      B

      NG (to Power management control ECU CAN main wire)

      C

    REPLACE NO. 5 CAN JUNCTION CONNECTOR

    CONNECT CONNECTORClick here

  5. CONNECT CONNECTOR

    1. Reconnect the H126 No. 5 CAN junction connector.

  6. CHECK FOR OPEN IN CAN BUS MAIN WIRE (ECM - NO. 5 CAN JUNCTION CONNECTOR)

    1. U184726E02

      Disconnect the ECM connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A76-13 (CANP) - A76-12 (CANN)

      Cable disconnected from negative (-) battery terminal

      108 to 132 Ω
      Table 7. Text in Illustration

      *a

      Front view of wire harness connector

      (to ECM)

    REPLACE ECM

    (Click here)

    REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO ECM (ECM - NO. 5 CAN JUNCTION CONNECTOR)

  7. CONNECT CONNECTOR

    1. Reconnect the H126 No. 5 CAN junction connector.

  8. CHECK FOR OPEN IN CAN BUS MAIN WIRE (POWER MANAGEMENT CONTROL ECU - NO. 5 CAN JUNCTION CONNECTOR)

    1. U122863E02

      Disconnect the 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

      H71-12 (CA3P) - H71-11 (CA3N)

      Cable disconnected from negative (-) battery terminal

      108 to 132 Ω
      Table 8. Text in Illustration

      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)
      Table 9. Result

      Result

      Proceed to

      OK (for LHD)

      A

      OK (for RHD)

      B

      NG

      C

    REPLACE POWER MANAGEMENT CONTROL ECU

    (Click here)

    REPLACE POWER MANAGEMENT CONTROL ECU

    (Click here)

    REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO POWER MANAGEMENT CONTROL ECU (POWER MANAGEMENT CONTROL ECU - NO. 5 CAN JUNCTION CONNECTOR)

  9. CHECK FOR SHORT IN CAN BUS WIRES (NO. 5 CAN JUNCTION CONNECTOR)

    1. Disconnect the No. 5 CAN junction connector.

      U184700E02
      Table 10. Text in Illustration

      *a

      Rear view of wire harness connector

      (to No. 5 CAN Junction Connector)

      *b

      to ECM

      *c

      to Power Management Control ECU

      *d

      to Air Conditioning Amplifier Assembly

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      Connected to

      H126-5 (CANH) - H126-16 (CANL)

      Cable disconnected from negative (-) battery terminal

      108 to 132 Ω

      ECM

      H126-6 (CANH) - H126-17 (CANL)

      Cable disconnected from negative (-) battery terminal

      108 to 132 Ω

      Power management control ECU

      H126-7 (CANH) - H126-18 (CANL)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      Air conditioning amplifier assembly
      Table 11. Result

      Result

      Proceed to

      OK

      A

      NG (to ECM CAN main wire)

      B

      NG (to Power management control ECU CAN main wire)

      C

      NG (ECU or sensor CAN branch wire)

      D

    REPLACE NO. 5 CAN JUNCTION CONNECTOR

    CONNECT CONNECTORClick here

    CHECK FOR SHORT IN CAN BUS WIRES (ECU, SENSOR)Click here

  10. CONNECT CONNECTOR

    1. Reconnect the H126 No. 5 CAN junction connector.

  11. CHECK FOR SHORT IN CAN BUS WIRES (ECM - NO. 5 CAN JUNCTION CONNECTOR)

    1. U184726E02

      Disconnect the ECM connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A76-13 (CANP) - A76-12 (CANN)

      Cable disconnected from negative (-) battery terminal

      108 to 132 Ω
      Table 12. Text in Illustration

      *a

      Front view of wire harness connector

      (to ECM)

    REPLACE ECM

    (Click here)

    REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO ECM (ECM - NO. 5 CAN JUNCTION CONNECTOR)

  12. CONNECT CONNECTOR

    1. Reconnect the H126 No. 5 CAN junction connector.

  13. CHECK FOR SHORT IN CAN BUS WIRES (POWER MANAGEMENT CONTROL ECU - NO. 5 CAN JUNCTION CONNECTOR)

    1. U122863E02

      Disconnect the 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

      H71-12 (CA3P) - H71-11 (CA3N)

      Cable disconnected from negative (-) battery terminal

      108 to 132 Ω
      Table 13. Text in Illustration

      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)
      Table 14. Result

      Result

      Proceed to

      OK (for LHD)

      A

      OK (for RHD)

      B

      NG

      C

    REPLACE POWER MANAGEMENT CONTROL ECU

    (Click here)

    REPLACE POWER MANAGEMENT CONTROL ECU

    (Click here)

    REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO POWER MANAGEMENT CONTROL ECU (POWER MANAGEMENT CONTROL ECU - NO. 5 CAN JUNCTION CONNECTOR)

  14. CHECK FOR SHORT IN CAN BUS WIRES (ECU, SENSOR)

    1. U184691E02

      Reconnect the CAN junction connector.

    2. Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the short circuited branch line is connected.

    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

      H71-12 (CA3P) - H71-11 (CA3N)

      Cable disconnected from negative (-) battery terminal

      54 to 69 Ω
      Table 15. Text in Illustration

      *a

      Component with harness connected

      (to Power Management Control ECU)

    REPLACE CORRESPONDING ECU OR SENSOR

    REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR CAN WIRE OR CONNECTOR

  15. CHECK FOR SHORT IN CAN BUS WIRES (NO. 5 CAN JUNCTION CONNECTOR)

    1. Disconnect the No. 5 CAN junction connector.

      U184777E02
      Table 16. Text in Illustration

      *a

      Rear view of wire harness connector

      (to No. 5 CAN Junction Connector)

      *b

      Front view of DLC3

      *c

      to ECM

      *d

      to Power Management Control ECU

      *e

      to Air Conditioning Amplifier Assembly

      -

      -

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      Connected to

      H126-5 (CANH) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      ECM

      H126-16 (CANL) - H16-4 (CG)

      H126-5 (CANH) - H16-16 (BAT)

      Cable disconnected from negative (-) battery terminal

      6 kΩ or higher

      H126-16 (CANL) - H16-16 (BAT)

      H126-6 (CANH) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      Power management control ECU

      H126-17 (CANL) - H16-4 (CG)

      H126-6 (CANH) - H16-16 (BAT)

      Cable disconnected from negative (-) battery terminal

      6 kΩ or higher

      H126-17 (CANL) - H16-16 (BAT)

      H126-7 (CANH) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      Air conditioning amplifier assembly

      H126-18 (CANL) - H16-4 (CG)

      H126-7 (CANH) - H16-16 (BAT)

      Cable disconnected from negative (-) battery terminal

      6 kΩ or higher

      H126-18 (CANL) - H16-16 (BAT)
      Table 17. Result

      Result

      Proceed to

      OK

      A

      NG (to Power management control ECU CAN main wire)

      B

      NG (ECU or sensor CAN wire)

      C

    REPLACE NO. 5 CAN JUNCTION CONNECTOR

    CHECK FOR SHORT IN CAN BUS WIRES (ECU, SENSOR)Click here

  16. CONNECT CONNECTOR

    1. Reconnect the H126 No. 5 CAN junction connector.

  17. CHECK FOR SHORT IN CAN BUS WIRES (POWER MANAGEMENT CONTROL ECU - NO.5 CAN JUNCTION CONNECTOR)

    1. U123105E02

      Disconnect the 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

      H71-12 (CA3P) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      H71-11 (CA3N) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      H71-12 (CA3P) - H16-16 (BAT)

      Cable disconnected from negative (-) battery terminal

      6 kΩ or higher

      H71-11 (CA3N) - H16-16 (BAT)

      Cable disconnected from negative (-) battery terminal

      6 kΩ or higher
      Table 18. Text in Illustration

      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      *b

      Front view of DLC3
      Table 19. Result

      Result

      Proceed to

      OK (for LHD)

      A

      OK (for RHD)

      B

      NG

      C

    REPLACE POWER MANAGEMENT CONTROL ECU

    (Click here)

    REPLACE POWER MANAGEMENT CONTROL ECU

    (Click here)

    REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO POWER MANAGEMENT CONTROL ECU (POWER MANAGEMENT CONTROL ECU - NO. 5 CAN JUNCTION CONNECTOR)

  18. CHECK FOR SHORT IN CAN BUS WIRES (ECU, SENSOR)

    1. U122875E02

      Reconnect the CAN junction connector.

    2. Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the bus line shorted to +B, GND is connected.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H71-12 (CA3P) - H71-6 (GND)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      H71-11 (CA3N) - H71-6 (GND)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      H71-12 (CA3P) - H71-1 (AM22)

      Cable disconnected from negative (-) battery terminal

      6 kΩ or higher

      H71-11 (CA3N) - H71-1 (AM22)

      Cable disconnected from negative (-) battery terminal

      6 kΩ or higher
      Table 20. Text in Illustration

      *a

      Component with harness connected

      (to Power Management Control ECU)

    REPLACE CORRESPONDING ECU OR SENSOR

    REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR CAN WIRE OR CONNECTOR

  19. CHECK FOR OPEN IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU CAN MAIN WIRE)

    1. U123136E02

      Disconnect the 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

      H72-4 (CA3P) - H72-3 (CA3N)

      Cable disconnected from negative (-) battery terminal

      108 to 132 Ω
      Table 21. Text in Illustration

      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

    REPLACE CAN MAIN WIRE CONNECTED TO POWER MANAGEMENT CONTROL ECU (CA3P, CA3N)

  20. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - BATTERY AND BODY GROUND)

    1. U123137E02

      Connect the cable to the negative (-) battery terminal.

      Note:

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected (Click here).

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H72-12 (GND) - Body ground

      Always

      Below 1 Ω

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      H72-8 (AM21) - Body ground

      Always

      11 to 14 V

      H72-2 (IG2) - Body ground

      Ignition switch ON

      11 to 14 V
    Table 22. Text in Illustration

    *a

    Rear view of wire harness connector

    (to Power Management Control ECU)
    Table 23. Result

    Result

    Proceed to

    OK (for LHD)

    A

    OK (for RHD)

    B

    NG

    C

    REPLACE POWER MANAGEMENT CONTROL ECU

    (Click here)

    REPLACE POWER MANAGEMENT CONTROL ECU

    (Click here)

    REPAIR OR REPLACE HARNESS OR CONNECTOR