Last Modified: 01-30-2024 6.11:8.1.0 Doc ID: RM100000001EKNS
Model Year Start: 2019 Model: RAV4 HV Prod Date Range: [11/2018 - 08/2020]
Title: HYBRID / BATTERY CONTROL: MOTOR GENERATOR CONTROL SYSTEM (for 2WD with NICKEL METAL HYDRIDE BATTERY): P31241F,P312487; Lost Communication between Drive Motor "A" and HV ECU Circuit Intermittent; 2019 - 2020 MY RAV4 HV [11/2018 - 08/2020]

DTC

P31241F

Lost Communication between Drive Motor "A" and HV ECU Circuit Intermittent

DTC

P312487

Lost Communication between Drive Motor "A" and HV ECU Missing Message

DESCRIPTION

The motor generator control ECU, which is built into the inverter with converter assembly, controls the motor (MG2) based on commands from the hybrid vehicle control ECU assembly.

The motor generator control ECU (MG ECU) monitors communication data and detects malfunctions.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P31241F

Lost Communication between Drive Motor "A" and HV ECU Circuit Intermittent

Error in reception from hybrid vehicle control ECU assembly via serial communication (out of communication standard) detected when DTC P0C7917, P0D3319, P1C5D19 or P1C5F19 is stored.

(1 trip detection logic)
  • Wire harness or connector
  • Inverter with converter assembly
  • Hybrid vehicle control ECU assembly

Does not come on

Master Warning:

Does not come on

P312487

Lost Communication between Drive Motor "A" and HV ECU Missing Message

Error in reception from hybrid vehicle control ECU assembly via serial communication (out of communication standard)

(1 trip detection logic)
  • Wire harness or connector
  • Inverter with converter assembly
  • Hybrid vehicle control ECU assembly

Comes on

Master Warning:

Comes on

CONFIRMATION DRIVING PATTERN

HINT:

After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

Click here 2019 - 2020 MY RAV4 HV [11/2018 - 08/2020]; HYBRID / BATTERY CONTROL: MOTOR GENERATOR CONTROL SYSTEM (for 2WD with NICKEL METAL HYDRIDE BATTERY): UTILITY

  1. Connect the Techstream to the DLC3.
  2. Turn the power switch on (IG) and turn the Techstream on.
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  4. Turn the power switch off and wait for 2 minutes or more.
  5. Turn the power switch on (IG) and turn the Techstream on.
  6. With power switch on (IG) and wait for 2 minutes or more.
  7. Enter the following menus: Powertrain / Motor Generator / Utility / All Readiness.
  8. Check the DTC judgment result.

    HINT:

    • If the judgment result shows NORMAL, the system is normal.
    • If the judgment result shows ABNORMAL, the system has a malfunction.
    • If the judgment result shows INCOMPLETE, perform driving pattern again.

WIRING DIAGRAM

Refer to the wiring diagram for the Inverter Low-voltage Circuit.

Click here 2019 - 2020 MY RAV4 HV [11/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for 2WD with NICKEL METAL HYDRIDE BATTERY): Inverter Low-voltage Circuit+

CAUTION / NOTICE / HINT

CAUTION:

  • Before the following operations are conducted, take precautions to prevent electric shock by turning the power switch off, wearing insulated gloves, and removing the service plug grip from HV battery.
    • Inspecting the high-voltage system
    • Disconnecting the low voltage connector of the inverter with converter assembly
    • Disconnecting the low voltage connector of the HV battery
  • To prevent electric shock, make sure to remove the service plug grip to cut off the high voltage circuit before servicing the vehicle.
  • After removing the service plug grip from the HV battery, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
  • After removing the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.

    Click here 2019 - 2020 MY RAV4 HV [11/2018 - 08/2020]; HYBRID / BATTERY CONTROL: MOTOR GENERATOR CONTROL SYSTEM (for 2WD with NICKEL METAL HYDRIDE BATTERY): PRECAUTION

    HINT:

    Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

    *a

    Without waiting for 10 minutes

NOTICE:

After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

Click here 2019 - 2024 MY RAV4 RAV4 HV [11/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: PRECAUTION

PROCEDURE

1.

CLEAR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Motor Generator / Trouble Codes.

(e) Clear the DTCs.

Powertrain > Motor Generator > Clear DTCs

(f) Turn the power switch off.

NEXT

2.

CHECK DIAGNOSIS RELATED INFORMATION AND DTC OUTPUT (MOTOR GENERATOR)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG) and wait for 2 minutes or more.

(c) Enter the following menus: Powertrain / Motor Generator / Utility / Diagnosis Related Information.

Powertrain > Motor Generator > Utility

Tester Display

Diagnosis Related Information

(d) Enter the following menus: Powertrain / Motor Generator / Trouble Codes.

Powertrain > Motor Generator > Trouble Codes

(e) Check for DTCs.

Result

Proceed to

P31241F or P312487 is listed in Diagnosis Related Information or P31241F or P312487 is output.

A

P31241F and P312487 are not listed in Diagnosis Information and P31241F and P312487 are not output.

B

(f) Turn the power switch off.

B

CHECK FOR INTERMITTENT PROBLEMS

A

3.

CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY (CHECK WAVEFORM)

(a) Connect an oscilloscope between the hybrid vehicle control ECU assembly terminals specified in the following table.

(b) Turn the power switch on (IG).

(c) Measure the waveform.

*a

Component with harness connected

(Hybrid Vehicle Control ECU Assembly)

-

-

Item

Contents

Tester Connection

CH1: A29-4 (HMCH) - A30-3 (E1)

CH2: A29-14 (HMCL) - A30-3 (E1)

Equipment Setting

1 V/DIV., 200 μs./DIV.

Condition

Power switch on (IG)

Result

Proceed to

The waveform appears as shown in the illustration.

A

The waveform differs from the one shown in the illustration.

B

HINT:

  • Perform this inspection with the connector connected.
  • If pulses are generated, the shape of the waveform can be assumed to be normal.
  • The shape of the waveform may vary according to communication conditions.

(d) Turn the power switch off.

A

REFER TO REPLACE INVERTER WITH CONVERTER ASSEMBLY PARTS

B

4.

CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU ASSEMBLY CONNECTOR)

(a) Check the connector connections and contact pressure of the relevant terminals for the hybrid vehicle control ECU assembly connectors.

Click here 2019 - 2024 MY RAV4 RAV4 HV [11/2018 -        ]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: ELECTRONIC CIRCUIT INSPECTION PROCEDURE

OK:

The connectors are connected securely and there are no contact pressure problems.
NG

CONNECT SECURELY
OK

5.

CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

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

(b) Check the connection condition of the low voltage connectors of the inverter with converter assembly and the contact pressure of each terminal. Check the terminals for deformation, and the connector for water and foreign matter.

Click here 2019 - 2024 MY RAV4 RAV4 HV [11/2018 -        ]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: ELECTRONIC CIRCUIT INSPECTION PROCEDURE

NOTICE:

Before disconnecting the connector, confirm that it is properly connected by checking that the claws of the lock levers are engaged and that the connector cannot be pulled off.

OK:

- The connector is connected securely.

- The terminals are not deformed and are connected securely.

- No water or foreign matter in the connector.

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

HINT:

When connecting the connector, connect it with the lock levers raised. Rotate each lock lever downward and make sure that the connector is securely connected. When a lock lever is fully lowered, a click will be heard as its claw engages. After the click is heard, pull up on the connector to confirm that it is securely connected.
B

CONNECT SECURELY
C

REPAIR OR REPLACE HARNESS OR CONNECTOR
A

6.

CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU ASSEMBLY - INVERTER WITH CONVERTER ASSEMBLY)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

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

(b) Disconnect the A51 inverter with converter assembly connector.

(c) Disconnect the A29 hybrid vehicle control ECU assembly connector.

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

Standard Resistance (Check for Open):

Tester Connection

Condition

Specified Condition

A51-20 (HMCH) - A29-4 (HMCH)

Power switch off

Below 1 Ω

A51-19 (HMCL) - A29-14 (HMCL)

Power switch off

Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection

Condition

Specified Condition

A51-20 (HMCH) or A29-4 (HMCH) - Body ground and other terminals

Power switch off

10 kΩ or higher

A51-19 (HMCL) or A29-14 (HMCL) - Body ground and other terminals

Power switch off

10 kΩ or higher

*a

Front view of wire harness connector

(to Inverter with Converter Assembly)

*b

Front view of wire harness connector

(to Hybrid Vehicle Control ECU Assembly)

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

(f) Turn the power switch on (IG).

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A51-20 (HMCH) or A29-4 (HMCH) - Body ground and other terminals

Power switch on (IG)

Below 1 V

A51-19 (HMCL) or A29-14 (HMCL) - Body ground and other terminals

Power switch on (IG)

Below 1 V

NOTICE:

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

HINT:

As there might be an intermittent malfunction, inspect the following items even if the measured resistance is as specified.

Check that each connector between the inverter with converter assembly and hybrid vehicle control ECU assembly is not loose or disconnected.

(h) Turn the power switch off.

(i) Reconnect the A29 hybrid vehicle control ECU assembly connector.

(j) Reconnect the A51 inverter with converter assembly connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

7.

CHECK INVERTER WITH CONVERTER ASSEMBLY

(a) Disconnect the A29 hybrid vehicle control ECU assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A29-4 (HMCH) - A29-14 (HMCL)

Power switch off

80 to 170 Ω

*a

Front view of wire harness connector

(to Hybrid Vehicle Control ECU Assembly)

(c) Reconnect the A29 hybrid vehicle control ECU assembly connector.

OK

REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY 2019 MY RAV4 HV [11/2018 - 02/2019]; HYBRID / BATTERY CONTROL: HYBRID VEHICLE CONTROL ECU: REMOVAL 2019 MY RAV4 HV [02/2019 - 10/2019]; HYBRID / BATTERY CONTROL: HYBRID VEHICLE CONTROL ECU: REMOVAL 2020 MY RAV4 HV [10/2019 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID VEHICLE CONTROL ECU: REMOVAL

NG

REFER TO REPLACE INVERTER WITH CONVERTER ASSEMBLY PARTS