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DTC U1002: Lost Communication with Gateway Module (Power Management2): Procedure

  1. CHECK CAN BUS WIRE 
    1. Turn the power switch off.
    2. Measure the resistance according to the value(s) in the table below.
      Fig 1: Identifying L6 Connector Terminals
      GTY328050Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Switch Condition Specified Condition Result
      L6-31 (CA3P) - L6-30 (CA3N) Power switch off 54 to 69 Ω Below 54 Ω:
      Short circuit between bus lines
      70 Ω or higher:
      Open circuit in a main bus line
      L6-31 (CA3P) - L6-5 (E02) Power switch off 200 Ω or higher Below 200 Ω:
      CANH ground short
      L6-30 (CA3N) - L6-5 (E02) Power switch off 200 Ω or higher Below 200 Ω:
      CANL ground short
      TEXT IN ILLUSTRATION

      *1 Component with harness connected
      (Power Management Control ECU)
    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 Result
      L6-31 (CA3P) - L6-7 (AM21) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ:
      CANH +B short
      L6-30 (CA3N) - L6-7 (AM21) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ:
      CANL +B short

      Result

      Result Proceed to
      OK A
      Open circuit in CAN main bus wire B
      Short circuit between bus lines C
      • Ground short
      • +B short
      		 D

    B → See step   3 

    C → See step   6 

    D → See step   13 

    A: Go to next step 

  2. CHECK DTC OUTPUT 
    1. Clear the DTCs.
    2. Turn the power switch off.
    3. Turn the power switch on (IG), recheck the DTC.

      Result

      Result Proceed to
      U1002 is output from power management control ECU
      (Techstream display/Power Management2)      		 A
      Other DTC is output B

    B → GO TO CIRCUITS INDICATED BY OUTPUT DTCS 

    A → See step   16 

  3. CHECK FOR OPEN IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU) 
    1. Disconnect the power management control ECU connector.
      Fig 2: Identifying L6 Connector Terminals
      GTY236741Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Rear view of wire harness connector
      (to Power Management Control ECU)
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      L6-31 (CA3P) - L6-30 (CA3N) Power switch off 108 to 132 Ω

    NG → See step   4 

    OK → See step   16 

  4. CHECK FOR OPEN IN CAN BUS WIRE (ECM) 
    1. Reconnect the power management control ECU connector.
    2. Disconnect the ECM connector.
      Fig 3: Identifying ECU Connector Terminals
      GTY213971Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to ECM)
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      A57-12 (CANP) - A57-4 (CANN) Power switch off 108 to 132 Ω

    NG → See step   5 

    OK → See step   15 

  5. CHECK FOR OPEN IN CAN BUS WIRE (CAN NO. 4 J/C MAIN WIRE) 
    1. Reconnect the ECM connector.
    2. Disconnect the CAN No. 4 junction connector.
      Fig 4: Identifying L101 Connector Terminals
      GTY221290Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to CAN No. 4 Junction Connector)
      *2 to Power Management Control ECU
      *3 to ECM
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition Connected to
      L101-12 (CANH) - L101-1 (CANL) Power switch off 108 to 132 Ω Power management control ECU
      L101-15 (CANH) - L101-4 (CANL) Power switch off 108 to 132 Ω ECM

      Result

      Result Proceed to
      OK A
      NG (to power management ECU main wire) B
      NG (to ECM main wire) C

    B → REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 4 J/C - POWER MANAGEMENT CONTROL ECU) 

    C → REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 4 J/C - ECM) 

    A → REPLACE CAN NO. 4 JUNCTION CONNECTOR 

  6. CHECK FOR SHORT IN CAN BUS WIRES (POWER MANAGEMENT CONTROL ECU) 
    1. Disconnect the power management control ECU connector.
      Fig 5: Identifying L6 Connector Terminals
      GTY236741Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Rear view of wire harness connector
      (to Power Management Control ECU)
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      L6-31 (CA3P) - L6-30 (CA3N) Power switch off 108 to 132 Ω

    NG → See step   7 

    OK → See step   16 

  7. CHECK FOR SHORT IN CAN BUS WIRES (ECM) 
    1. Reconnect the power management control ECU connector.
    2. Disconnect the ECM connector.
      Fig 6: Identifying ECU Connector Terminals
      GTY213971Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to ECM)
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      A57-12 (CANP) - A57-4 (CANN) Power switch off 108 to 132 Ω

    NG → See step   8 

    OK → See step   15 

  8. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 4 J/C MAIN WIRE) 
    1. Reconnect the ECM connector.
    2. Disconnect the CAN No. 4 junction connector.
      Fig 7: Identifying L101 Connector Terminals
      GTY221290Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition Connected to
      L101-12 (CANH) - L101-1 (CANL) Power switch off 108 to 132 Ω Power management control ECU
      L101-15 (CANH) - L101-4 (CANL) Power switch off 108 to 132 Ω ECM
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to CAN No. 4 Junction Connector)
      *2 to Power Management Control ECU
      *3 to ECM

      Result

      Result Proceed to
      OK A
      NG (to Power management ECU main wire) B
      NG (to ECM main wire) C

    B → REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 4 J/C - POWER MANAGEMENT CONTROL ECU) 

    C → REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 4 J/C - ECM) 

    A: Go to next step 

  9. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 4 J/C - SKID CONTROL ECU) 
    1. Disconnect the skid control ECU (brake booster with master cylinder) connector.
    2. Measure the resistance according to the value(s) in the table below.
      Fig 8: Identifying L101 Connector Terminals
      GTY221289Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      L101-14 (CANH) - L101-3 (CANL) Power switch off 1 MΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to CAN No. 4 Junction Connector)
      *2 to Skid Control ECU

    NG → REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 4 J/C - SKID CONTROL ECU) 

    OK: Go to next step 

  10. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 4 J/C - A/C ECU) 
    1. Disconnect the air conditioning amplifier connector.
    2. Measure the resistance according to the value(s) in the table below.
      Fig 9: Identifying L101 Connector Terminals
      GTY221288Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      L101-13 (CANH) - L101-2 (CANL) Power switch off 1 MΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to CAN No. 4 Junction Connector)
      *2 to Air Conditioning Amplifier

    NG → REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 4 J/C - A/C ECU) 

    OK: Go to next step 

  11. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 4 J/C) 
    1. Reconnect the CAN No. 4 junction connector.
    2. Measure the resistance according to the value(s) in the table below.
      Fig 10: Identifying L6 Connector Terminals
      GTY236741Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      L6-31 (CA3P) - L6-30 (CA3N) Power switch off 108 to 132 Ω
      TEXT IN ILLUSTRATION

      *1 Rear view of wire harness connector
      (to Power Management Control ECU)
      NOTE:
      • The resistance must be measured after the ECM and CAN No. 4 J/C wire harness connector are reconnected.
      • The resistance must be measured after the skid control ECU and air conditioning amplifier connector are disconnected.

    NG → REPLACE CAN NO. 4 JUNCTION CONNECTOR 

    OK: Go to next step 

  12. CHECK FOR SHORT IN CAN BUS WIRES (AIR CONDITIONING AMPLIFIER) 
    1. Reconnect the air conditioning amplifier connector.
    2. Measure the resistance according to the value(s) in the table below.
      Fig 11: Identifying L6 Connector Terminals
      GTY236741Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      L6-31 (CA3P) - L6-30 (CA3N) Power switch off 108 to 132 Ω
      TEXT IN ILLUSTRATION

      *1 Rear view of wire harness connector
      (to Power Management Control ECU)
      NOTE:
      • The resistance must be measured after the air conditioning amplifier connector is reconnected.
      • The resistance must be measured after the skid control ECU connector is disconnected.

    NG → See step   17 

    OK → See step   18 

  13. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 4 J/C) 
    1. Disconnect the CAN No. 4 junction connector.
    2. Measure the resistance according to the value(s) in the table below.
      Fig 12: Identifying L101 And L61 Connector Terminals
      GTY221599Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Condition Specified Condition Purpose Connected to
      L101-12 (CANH) - L61-4 (CG) Power switch off 200 Ω or higher Inspection for CANH ground short Power management control ECU
      L101-1 (CANL) - L61-4 (CG) Power switch off 200 Ω or higher Inspection for CANL ground short
      L101-13 (CANH) - L61-4 (CG) Power switch off 200 Ω or higher Inspection for CANH ground short Air conditioning amplifier
      L101-2 (CANL) - L61-4 (CG) Power switch off 200 Ω or higher Inspection for CANL ground short
      L101-14 (CANH) - L61-4 (CG) Power switch off 200 Ω or higher Inspection for CANH ground short Skid control ECU
      L101-3 (CANL) - L61-4 (CG) Power switch off 200 Ω or higher Inspection for CANL ground short
      L101-15 (CANH) - L61-4 (CG) Power switch off 200 Ω or higher Inspection for CANH ground short ECM
      L101-4 (CANL) - L61-4 (CG) Power switch off 200 Ω or higher Inspection for CANL ground short
      L101-12 (CANH) - L61-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short Power management control ECU
      L101-1 (CANL) - L61-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short
      L101-13 (CANH) - L61-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short Air conditioning amplifier
      L101-2 (CANL) - L61-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short
      L101-14 (CANH) - L61-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short Skid control ECU
      L101-3 (CANL) - L61-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short
      L101-15 (CANH) - L61-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short ECM
      L101-4 (CANL) - L61-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short

      HINT: 

      • It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN Bus Wire inspection.
      • Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to CAN No. 4 Junction Connector)      		 *2 DLC3
      *3 to Power Management Control ECU *4 to Air Conditioning Amplifier
      *5 to Skid Control ECU *6 to ECM

    NG → See step   14 

    OK → REPLACE CAN NO. 4 JUNCTION CONNECTOR 

  14. CHECK FOR SHORT IN CAN BUS WIRES (ECU) 
    1. Disconnect the connector that includes terminals CANH and CANL from the ECU to which the bus wire shorted to B+ or shorted to GND is connected. Refer to TERMINALS OF ECU .
    2. Measure the resistance according to the value(s) in the table below.
      Fig 13: Identifying L6 Connector Terminals
      GTY328050Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Switch Condition Specified Condition Purpose
      L6-31 (CA3P) - L6-5 (E02) Power switch off 200 Ω or higher Below 200 Ω:
      CANH ground short
      L6-30 (CA3N) - L6-5 (E02) Power switch off 200 Ω or higher Below 200 Ω:
      CANL ground short
      L6-31 (CA3P) - L6-7 (AM21) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ:
      CANH +B short
      L6-30 (CA3N) - L6-7 (AM21) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ:
      CANL +B short
      TEXT IN ILLUSTRATION

      *1 Component with harness connected
      (Power Management Control ECU)

      HINT: 

      • It is only necessary to perform the inspection in the above table for the result (open or short circuit) that was obtained in the Check CAN Bus Wire inspection.

        Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.

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

    NG → REPAIR OR REPLACE CORRESPONDING ECU WIRE 

    OK → REPLACE CORRESPONDING ECU 

  15. REPLACE ECM. Refer to  REMOVAL 
  16. REPLACE POWER MANAGEMENT CONTROL ECU. Refer to  REMOVAL 
  17. REPLACE AIR CONDITIONING AMPLIFIER. Refer to  REMOVAL 
  18. REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (SKID CONTROL ECU). Refer to  REMOVAL 
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