LEMON Manuals: Even more car manuals for everyone
Home >> Toyota >> 2020 >> Avalon Limited >> Repair and Diagnosis >> Hybrid/Electric Powertrain >> Testing and Diagnosis >> Hybrid Control System (Nickel Metal Hydride) - Diagnostic Codes (P1C9F-P3147) >> HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY) >> DTC P3123-87: Lost Communication with Drive Motor Control Module "A" from Hybrid/EV Control Module Missing Message [04/2018 - 08/2020] >> Procedure

DTC P3123-87: Lost Communication with Drive Motor Control Module "A" from Hybrid/EV Control Module Missing Message [04/2018 - 08/2020]: Procedure

  1. INSPECT FUSE (PCU) 
    1. Remove the PCU fuse from the No. 4 relay block.
    2. Measure the resistance according to the value(s) in the table below.
      GTY844779Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 No. 4 Relay Block
      *2 PCU Fuse

      Standard Resistance

      Tester Connection Condition Specified Condition
      PCU fuse Always Below 1 Ω
    3. Install the PCU fuse.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  9

    Result: 

    OK 

    See step  2

  2. CLEAR DTC 

    Refer to PROCEDURE - Step 3

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  3

  3. CHECK DIAGNOSIS RELATED INFORMATION AND DTC OUTPUT (HYBRID CONTROL) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG) and wait for 2 minutes or more.
    3. Enter the following menus: Powertrain/Hybrid Control/Utility/Diagnosis Related Information.

      Powertrain > Hybrid Control > Utility 

      Tester Display
      Diagnosis Related Information
    4. Enter the following menus: Powertrain/Hybrid Control/Trouble Codes.

      Powertrain > Hybrid Control > Trouble Codes 

    5. Check for DTCs.

      Result

      Result  Proceed to
      P3123-87 is listed in Diagnosis Related Information or DTC P3123-87 is output. A
      P3123-87 is not listed in Diagnosis Information and DTC P3123-87 is not output. B
    6. Turn the power switch off.

    Result: 

    B 

    CHECK FOR INTERMITTENT PROBLEMS. Refer to  CHECK FOR INTERMITTENT PROBLEMS [04/2018 - 08/2020] 

    Result: 

    A 

    See step  4

  4. CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR) 

    Refer to PROCEDURE - Step 1

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    CONNECT SECURELY 

    Result: 

    OK 

    See step  5

  5. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR) 

    Refer to PROCEDURE - Step 3

    Result

    Result Proceed to
    OK A
    NG (The connector is not connected securely.) B
    NG (The terminals are not making secure contact or are deformed, or water or foreign matter exists in the connector.) C

    Result: 

    B 

    CONNECT SECURELY 

    Result: 

    C 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    A 

    See step  6

  6. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY POWER SOURCE CIRCUIT) 
    WARNING:

    Be sure to wear insulated gloves.

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

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

    2. Disconnect the A42 inverter with converter assembly connector.
    3. Measure the resistance according to the value(s) in the table below.
      GTY938401Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Inverter with Converter Assembly)

      Standard Resistance

      Tester Connection Condition Specified Condition
      A42-24 (GND1) - Body ground Power switch off Below 1 Ω
      A42-23 (GND2) - Body ground Power switch off Below 1 Ω
    4. Connect the cable to the negative (-) auxiliary battery terminal.
    5. Turn the power switch on (IG).
    6. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A42-6 (+B) - Body ground Power switch on (IG) 11 to 14 V
      A42-5 (+B2) - Body ground Power switch on (IG) 11 to 14 V
      NOTE:

      Turning the power switch on (IG) with the inverter with converter assembly disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

    7. Turn the power switch off.
    8. Disconnect the cable from the negative (-) auxiliary battery terminal.
    9. Reconnect the A42 inverter with converter assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - HYBRID VEHICLE CONTROL ECU) 
    WARNING:

    Be sure to wear insulated gloves.

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

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

    2. Disconnect the A42 inverter with converter assembly connector.
    3. Disconnect the A24 hybrid vehicle control ECU connector.
    4. Connect the cable to the negative (-) auxiliary battery terminal.
    5. Turn the power switch on (IG).
    6. Measure the voltage according to the value(s) in the table below.
      GTY940872Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Inverter with Converter Assembly)
      *b Rear view of wire harness connector
      (to Hybrid Vehicle Control ECU)

      Standard Voltage

      Tester Connection Condition Specified Condition
      A24-30 (HMCL) - Body ground Power switch on (IG) Below 1 V
      A24-31 (HMCH) - Body ground Power switch on (IG) Below 1 V
      NOTE:

      Turning the power switch on (IG) with the hybrid vehicle control ECU connector and the inverter with converter assembly disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

    7. Turn the power switch off.
    8. Disconnect the cable from the negative (-) auxiliary battery terminal and wait for 2 minutes or more.
    9. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      A42-19 (HMCL) - A24-30 (HMCL) Power switch off Below 1 Ω
      A42-20 (HMCH) - A24-31 (HMCH) Power switch off Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      A42-19 (HMCL) or A24-30 (HMCL) - Body ground and other terminals Power switch off 10 kΩ or higher
      A42-20 (HMCH) or A24-31 (HMCH) - Body ground and other terminals Power switch off 10 kΩ or higher
    10. Reconnect the A24 hybrid vehicle control ECU connector.
    11. Reconnect the A42 inverter with converter assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  8

  8. CHECK HYBRID VEHICLE CONTROL ECU 
    WARNING:

    Be sure to wear insulated gloves.

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

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

    2. Disconnect the A42 inverter with converter assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A24-30 (HMCL) -A24-31 (HMCH) Power switch off 110 to 130 Ω
      GTY907627Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Hybrid Vehicle Control ECU)
    4. Reconnect the A42 inverter with converter assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE INVERTER WITH CONVERTER ASSEMBLY. Refer to  REMOVAL [04/2018 - 08/2020] 

    Result: 

    NG 

    REPLACE HYBRID VEHICLE CONTROL ECU. Refer to  REMOVAL [04/2018 - 08/2021] 

  9. REPLACE FUSE (PCU) 
    1. Replace the PCU fuse.
      GTY742442Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 No. 4 Relay Block
      *2 PCU Fuse
    2. Turn the power switch on (READY).
    3. Check if there is an open circuit in the PCU fuse in the No. 4 relay block.

      OK

      There is no open circuit in the PCU fuse.

      HINT: 

      If the fuse does not become open again after turning the power switch on (READY), it can be assumed that the previous fuse failed due to age.

    4. Turn the power switch off.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END 

    Result: 

    NG 

    See step  10

  10. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - PCU FUSE) 
    WARNING:

    Be sure to wear insulated gloves.

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

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

    2. Remove the PCU fuse from the No. 4 relay block.
    3. Disconnect the A42 inverter with converter assembly connector.
    4. Measure the resistance according to the value(s) in the table below.
      GTY839852Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 No. 4 Relay Block *2 PCU Fuse Holder
      *a Front view of wire harness connector
      (to Inverter with Converter Assembly)      		 - -

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      A42-6 (+B), A42-5 (+B2) or 2 (PCU fuse holder) - Body ground and other terminals Power switch off 10 kΩ or higher
    5. Reconnect the A42 inverter with converter assembly connector.
    6. Install the PCU fuse.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  12

    Result: 

    OK 

    See step  11

  11. REPLACE INVERTER WITH CONVERTER ASSEMBLY 

    Refer to REMOVAL [04/2018 - 08/2020]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    REPLACE FUSE (PCU) 

  12. REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    REPLACE FUSE (PCU) 

scientia non olet · About LEMON Manuals