LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2024 >> TX 350 Base, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 17 (Hybrid Control System - Diagnostic Codes (6 Of 6) & Circuit Tests) >> HYBRID CONTROL SYSTEM (for PHEV Model) >> DTC U117B-87: Lost Communication with Hybrid/EV Battery Energy Control Module "A" (ch2) Missing Message [12/2023 - ] >> Procedure

DTC U117B-87: Lost Communication with Hybrid/EV Battery Energy Control Module "A" (ch2) Missing Message [12/2023 - ]: Procedure

WARNING: This page is about a different car, the 2024 Lexus TX 550h+. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK DTC OUTPUT (HV BATTERY) 

    Pre-procedure1

    • None.
    • Check and record any HV battery system DTCs and freeze frame data. Check for DTCs.

      Powertrain > HV Battery > Trouble Codes 

      Result

      Result Proceed to
      DTCs related to HV Battery are not output. A
      DTCs related to HV Battery are output. B

    Post-procedure1

    • Turn the ignition switch off.

    Result: 

    B 

    GO TO DTC CHART (HYBRID BATTERY SYSTEM). Refer to  DIAGNOSTIC TROUBLE CODE CHART [12/2023 - ] 

    Result: 

    A 

    See step  2

  2. CHECK BATTERY ECU ASSEMBLY (BATTERY ECU ASSEMBLY POWER SOURCE CIRCUIT) 
    WARNING:

    Be sure to wear insulated gloves.

    Pre-procedure1

    • Check that the service plug grip is not installed.
      NOTE:

      After removing the service plug grip, do not turn the ignition switch to ON (READY), unless instructed by the service information because this may cause a malfunction.

    • Connect the SST.

      HINT: 

      Refer to Instructions for Connecting SST [12/2023 - ]

    • Disconnect the battery ECU assembly connector.
      GTY1231590Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    • Connect the cable to the negative (-) auxiliary battery terminal.
    • Turn the ignition switch to ON.
    • Measure the voltage according to the value(s) in the table below.
      GTY1230505Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Battery ECU Assembly)

      Standard Voltage

      Tester Connection Condition Specified Condition Result
      j3-1 (AM) - Body ground Ignition switch off 11 to 14 V V
      j3-5 (IGCT) - Body ground Ignition switch ON 11 to 14 V V
      NOTE:

      Turning the ignition switch to ON with the service plug grip removed causes other DTCs to be stored. Clear the DTCs after performing this inspection.

      HINT: 

      As there might be an intermittent malfunction in the battery ECU assembly power source circuit, inspect the following even if the measured voltage is as specified:

      • Installation condition of fuse(s) (before removing fuse(s)) (Power Source Circuit)
      • Fuse condition (before and after removing fuse(s)) (Power Source Circuit)
      • Connection condition of connectors (Power Source Circuit)
      • Wire harness condition (Power Source Circuit)
      • Wire harness condition (GND circuit)
    • Turn the ignition switch off.
    • Disconnect the cable from the negative (-) auxiliary battery terminal.
    • Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      j3-25(GND) - Body ground Ignition switch off Below 1 Ω Ω
      j3-26(GND1) - Body ground Ignition switch off Below 1 Ω Ω
      j3-27(GND2) - Body ground Ignition switch off Below 1 Ω Ω

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • Reconnect the battery ECU assembly connector.
    • Disconnect the SST.

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY ECU ASSEMBLY POWER SOURCE CIRCUIT) 

    Result: 

    OK 

    See step  3

  3. CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY 
    WARNING:

    Be sure to wear insulated gloves.

    Pre-procedure1

    • Check that the service plug grip is not installed.
      NOTE:

      After removing the service plug grip, do not turn the ignition switch to ON (READY), unless instructed by the service information because this may cause a malfunction.

    • Connect the SST.

      HINT: 

      Refer to Instructions for Connecting SST [12/2023 - ]

    • Disconnect the battery ECU assembly connector.
      GTY1231590Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    • Measure the resistance according to the value(s) in the table below.
      GTY1230506Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Battery ECU Assembly)

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      j3-7 (CA1H) - j3-8 (CA1L) Ignition switch off 108 to 132 Ω Ω

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • Reconnect the battery ECU assembly connector.
    • Disconnect the SST.

    Result: 

    OK 

    REPLACE BATTERY ECU ASSEMBLY. Refer to  REMOVAL [12/2023 - ] 

    Result: 

    NG 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU ASSEMBLY - BATTERY ECU ASSEMBLY) 
    WARNING:

    Be sure to wear insulated gloves.

    Pre-procedure1

    • Check that the service plug grip is not installed.
      NOTE:

      After removing the service plug grip, do not turn the ignition switch to ON (READY), unless instructed by the service information because this may cause a malfunction.

    • Disconnect the hybrid vehicle control ECU assembly connector.
      NOTE:
      • Before disconnecting the connector, check that it is not loose or disconnected.
      • Check that each connector between the hybrid vehicle control ECU assembly and battery ECU assembly is not loose or disconnected.
    • Disconnect the shift control actuator assembly (shift actuator ECU) connector.
    • Disconnect the transmission floor shift assembly (shift control ECU) connector.
    • Disconnect the electric vehicle charger assembly connector.
    • Connect the SST.

      HINT: 

      Refer to Instructions for Connecting SST [12/2023 - ]

    • Disconnect the battery ECU assembly connector.
      NOTE:
      • Before disconnecting the connector, check that it is not loose or disconnected.
      • Check the terminals of the connector for deformation and corrosion.
      GTY1231590Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    • Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      j3-7 (CA1H) - D117-9 (CA4H) Ignition switch off Below 1 Ω Ω
      j3-8 (CA1L) - D117-22 (CA4L) Ignition switch off Below 1 Ω Ω
      D117-9 (CA4H) - Other terminals and body ground Ignition switch off 10 kΩ or higher kΩ
      D117-22 (CA4L) - Other terminals and body ground Ignition switch off 10 kΩ or higher kΩ
      NOTE:

      Make sure that each connector between the battery ECU assembly and hybrid vehicle control ECU assembly is not loose or disconnected and its terminals are not deformed or corroded.

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • Reconnect the battery ECU assembly connector.
    • Disconnect the SST.
    • Reconnect the electric vehicle charger assembly connector.
    • Reconnect the transmission floor shift assembly (shift control ECU) connector.
    • Reconnect the shift control actuator assembly (shift actuator ECU) connector.
    • Reconnect the hybrid vehicle control ECU assembly connector.

    Result: 

    OK 

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY. Refer to  REMOVAL [12/2023 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

scientia non olet · About LEMON Manuals