LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2015 >> RX 350 Base, FWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Communication Devices >> Can Communication System (Diagnostic Codes & Circuit Tests) >> Can Communication System >> DTC U1002: Lost Communication with Gateway Module (Power Management2) [03/2014 - ] >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC U1002: Lost Communication with Gateway Module (Power Management2) [03/2014 - ]: Procedure

  1. CHECK CAN BUS WIRE 
    1. Turn the engine switch off.
    2. Measure the resistance according to the value(s) in the table below.
      GTY352030Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

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

      Standard Resistance

      Tester Connection Switch Condition Specified Condition Result
      F8-12 (CA3P) - F8-11 (CA3N) Engine switch off 54 to 69 Ω Below 54 Ω:
      Short circuit between bus wires
      70 Ω or higher:
      Open circuit in a main bus wire
      F8-12 (CA3P) - F8-6 (GND) Engine switch off 200 Ω or higher Below 200 Ω:
      CANH ground short
      F8-11 (CA3N) - F8-6 (GND) Engine switch off 200 Ω or higher Below 200 Ω:
      CANL ground short
    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
      F8-12 (CA3P) - F8-1 (AM22) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ:
      CANH +B short
      F8-11 (CA3N) - F8-1 (AM22) 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 wires C
      • Ground short
      • +B short
      		 D

    B → See step   2 

    C → See step   5 

    D → See step   9 

    A → See step   14 

  2. CHECK FOR OPEN IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU) 
    1. Disconnect the power management control ECU connector.
      GTY348435Courtesy 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
      F8-12 (CA3P) - F8-11 (CA3N) Engine switch off 108 to 132 Ω

    NG → See step   3 

    OK → See step   14 

  3. CHECK FOR OPEN IN CAN BUS WIRE (ECM) 
    1. Reconnect the power management control ECU connector.
    2. Disconnect the ECM connector.
      GTY277155Courtesy 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
      A43-8 (CANP) - A43-9 (CANN) Engine switch off 108 to 132 Ω

    NG → See step   4 

    OK → See step   13 

  4. CHECK FOR OPEN IN CAN BUS WIRE (CAN NO. 7 J/C MAIN WIRE) 
    1. Reconnect the ECM connector.
    2. Disconnect the CAN No. 7 junction connector.
      GTY353252Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to CAN No. 7 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
      F72-2 (CANH) - F72-13 (CANL) Engine switch off 108 to 132 Ω
      F72-3 (CANH) - F72-14 (CANL) Engine switch off 108 to 132 Ω

      Result

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

    B → REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 7 J/C - ECM) 

    C → REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 7 J/C - POWER MANAGEMENT CONTROL ECU) 

    A → REPLACE CAN NO. 7 JUNCTION CONNECTOR 

  5. CHECK FOR SHORT IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU) 
    1. Disconnect the power management control ECU connector.
      GTY348435Courtesy 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
      F8-12 (CA3P) - F8-11 (CA3N) Engine switch off 108 to 132 Ω

    NG → See step   6 

    OK → See step   14 

  6. CHECK FOR SHORT IN CAN BUS WIRES (ECM) 
    1. Reconnect the power management control ECU connector.
    2. Disconnect the ECM connector.
      GTY277155Courtesy 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
      A43-8 (CANP) - A43-9 (CANN) Engine switch off 108 to 132 Ω

    NG → See step   7 

    OK → See step   13 

  7. CHECK FOR SHORT IN CAN BUS MAIN WIRE (CAN NO. 7 J/C MAIN WIRE) 
    1. Reconnect the ECM connector.
    2. Disconnect the CAN No. 7 junction connector.
      GTY353252Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to CAN No. 7 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
      F72-2 (CANH) - F72-13 (CANL) Engine switch off 108 to 132 Ω
      F72-3 (CANH) - F72-14 (CANL) Engine switch off 108 to 132 Ω

      Result

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

    B → REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 7 J/C - ECM) 

    C → REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 7 J/C - POWER MANAGEMENT CONTROL ECU) 

    A: Go to next step 

  8. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 7 J/C - A/C ECU) 
    1. Disconnect the air conditioning amplifier connector.
    2. Disconnect the CAN No. 7 junction connector.
      GTY353264Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to CAN No. 7 Junction Connector)
      *2 to Air Conditioning Amplifier
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      F72-1 (CANH) - F72-12 (CANL) Engine switch off 1 MΩ or higher

    NG → REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 7 J/C - A/C ECU) 

    OK → See step   15 

  9. CHECK FOR SHORT IN CAN BUS WIRES (POWER MANAGEMENT CONTROL ECU) 
    1. Disconnect the power management control ECU connector.
      GTY348434Courtesy 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 Condition Specified Condition Purpose
      F8-12 (CA3P) - F8-6 (GND) Engine switch off 200 Ω or higher Inspection for CANH ground short
      F8-11 (CA3N) - F8-6 (GND) Engine switch off 200 Ω or higher Inspection for CANL ground short
      F8-12 (CA3P) - F8-1 (AM22) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F8-11 (CA3N) - F8-1 (AM22) 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 (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.

    NG → See step   10 

    OK → See step   14 

  10. CHECK FOR SHORT IN CAN BUS WIRES (ECM) 
    1. Disconnect the ECM connectors.
      GTY354962Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

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

      Standard Resistance

      Tester Connection Condition Specified Condition Purpose
      A43-8 (CANP) - D1-81 (E1) Engine switch off 200 Ω or higher Inspection for CANH ground short
      A43-9 (CANN) - D1-81 (E1) Engine switch off 200 Ω or higher Inspection for CANL ground short
      A43-8 (CANP) - A43-1 (BATT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      A43-9 (CANN) - A43-1 (BATT) 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 (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.

    NG → See step   11 

    OK → See step   13 

  11. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 7 J/C MAIN WIRE) 
    1. Disconnect the CAN No. 7 junction connector.
      GTY356647Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to CAN No. 7 junction connector)
      *2 to Power Management Control ECU
      *3 to ECM
      *4 DLC3
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Purpose Connected to
      F72-2 (CANH) - F17-4 (CG) Engine switch off 200 Ω or higher Inspection for CANH ground short Power management control ECU
      F72-13 (CANL) - F17-4 (CG) Engine switch off 200 Ω or higher Inspection for CANL ground short
      F72-2 (CANH) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F72-13 (CANL) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short
      F72-3 (CANH) - F17-4 (CG) Engine switch off 200 Ω or higher Inspection for CANH ground short ECM
      F72-14 (CANL) - F17-4 (CG) Engine switch off 200 Ω or higher Inspection for CANL ground short
      F72-3 (CANH) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F72-14 (CANL) - F17-16 (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 (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.

      Result

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

    B → REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 7 J/C - ECM) 

    C → REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 7 J/C - POWER MANAGEMENT CONTROL ECU) 

    A: Go to next step 

  12. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 7 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.
      GTY359396Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to CAN No. 7 junction connector)
      *2 to Air Conditioning Amplifier
      *3 DLC3

      Standard Resistance

      Tester Connection Condition Specified Condition Purpose
      F72-1 (CANH) - F17-4 (CG) Engine switch off 200 Ω or higher Inspection for CANH ground short
      F72-12 (CANL) - F17-4 (CG) Engine switch off 200 Ω or higher Inspection for CANL ground short
      F72-1 (CANH) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F72-12 (CANL) - F17-16 (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 (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.

    NG → REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 7 J/C - A/C ECU) 

    OK → See step   15 

  13. REPLACE ECM. Refer to  REMOVAL [03/2014 - ] 
  14. REPLACE POWER MANAGEMENT CONTROL ECU. Refer to  REMOVAL [03/2014 - ] 
  15. REPLACE AIR CONDITIONING AMPLIFIER. Refer to  REMOVAL [03/2014 - ] 
scientia non olet · About LEMON Manuals