Last Modified: 01-30-2024 6.11:8.1.0 Doc ID: RM100000001PEFQ
Model Year Start: 2020 Model: RAV4 HV Prod Date Range: [06/2020 -           ]
Title: HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for AWD with NICKEL METAL HYDRIDE BATTERY): U029A87; Lost Communication with Hybrid/EV Battery Sensor Module Missing Message; 2020 - 2024 MY RAV4 HV [06/2020 -        ]

DTC

U029A87

Lost Communication with Hybrid/EV Battery Sensor Module Missing Message

DESCRIPTION

The battery voltage sensor detects the HV battery conditions (voltage, current and temperature) and the battery cooling fan frequency, and sends the detected signals to the hybrid vehicle control ECU assembly via serial communication. (The hybrid vehicle control ECU assembly does not send signals to the battery voltage sensor.)

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

U029A87

Lost Communication with Hybrid/EV Battery Sensor Module Missing Message

Serial communication error between the hybrid vehicle control ECU assembly and battery voltage sensor: The hybrid vehicle control ECU assembly cannot receive signals from the battery voltage sensor correctly.

(1 trip detection logic)
  • Hybrid vehicle control ECU assembly
  • Battery voltage sensor
  • Wire harness or connector

Comes on

Master Warning:

Comes on

MONITOR DESCRIPTION

If a malfunction in communication line between the battery voltage sensor and hybrid vehicle control ECU assembly is detected, the hybrid vehicle control ECU assembly will illuminate the MIL and store a DTC.

MONITOR STRATEGY

Related DTCs

U029A (INF U029A87): Battery voltage sensor communication malfunction

Required sensors/components

Main: Battery voltage sensor

Sub: Communication line

Frequency of operation

Continuous

Duration

TMC's intellectual property

MIL operation

Immediately

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

The monitor will run whenever the following DTCs are not stored

TMC's intellectual property

Other conditions belong to TMC's intellectual property

-

TYPICAL MALFUNCTION THRESHOLDS

TMC's intellectual property

-

COMPONENT OPERATING RANGE

Battery voltage sensor

DTC U029A (INF U029A87) is not detected

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 - 2024 MY RAV4 HV [02/2019 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for AWD with NICKEL METAL HYDRIDE BATTERY): UTILITY

  • When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.

    Click here 2019 - 2022 MY RAV4 HV [02/2019 - 10/2022]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for AWD with NICKEL METAL HYDRIDE BATTERY): DTC CHECK / CLEAR 2023 - 2024 MY RAV4 HV [10/2022 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for AWD with NICKEL METAL HYDRIDE BATTERY): DTC CHECK / CLEAR

  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON and turn the Techstream on.
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  4. Turn the ignition switch off and wait for 2 minutes or more.
  5. Turn the ignition switch to ON and turn the Techstream on.
  6. With ignition switch ON and wait for 2 minutes or more. [*1]

    HINT:

    [*1]: Normal judgment procedure.

    The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.

  7. Enter the following menus: Powertrain / Hybrid Control / 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 the normal judgment procedure again.

WIRING DIAGRAM

Refer to the wiring diagram for DTC P0AFC00.

Click here 2020 - 2024 MY RAV4 HV [06/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for AWD with NICKEL METAL HYDRIDE BATTERY): P0AFC00,P0AFC16,P0AFC96,P308A12; Hybrid/EV Battery Sensor Module+

CAUTION / NOTICE / HINT

CAUTION:

  • Before the following operations are conducted, take precautions to prevent electric shock by turning the ignition 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 - 2024 MY RAV4 HV [02/2019 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for AWD 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.

    *1

    Without waiting for 10 minutes

NOTICE:

After turning the ignition 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.

CHECK DTC OUTPUT (HYBRID CONTROL)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

(d) Check and record any HV system DTCs and freeze frame data. Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes

Result

Proceed to

Only "U029A87" is output.

A

DTCs other than "U029A87" are also output.

B

(e) Turn the ignition switch off.

B

GO TO DTC CHART (HYBRID CONTROL SYSTEM) 2020 - 2021 MY RAV4 HV [06/2020 - 12/2021]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for AWD with NICKEL METAL HYDRIDE BATTERY): DIAGNOSTIC TROUBLE CODE CHART 2022 - 2024 MY RAV4 HV [12/2021 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for AWD with NICKEL METAL HYDRIDE BATTERY): DIAGNOSTIC TROUBLE CODE CHART

A

2.

CHECK CONNECTOR CONNECTION CONDITION (INTERMEDIATE CONNECTOR)

(a) Check that the AN2 intermediate connector which connects the battery voltage sensor to the hybrid vehicle control ECU is securely connected with no deformation, and that there is no contamination by water or foreign matter.

HINT:

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

For vehicles in which the intermediate connector is inside the relay block, check for signs of water intrusion inside the relay block.

OK:

- The connector is connected securely.

- The terminals are not deformed and are connected securely.

- No water or foreign matter in the connectors.

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
B

CONNECT SECURELY
C

REPAIR OR REPLACE HARNESS OR CONNECTOR
A

3.

CHECK CONNECTOR CONNECTION CONDITION (INTERMEDIATE CONNECTOR)

(a) Check that the NN11 intermediate connector which connects the battery voltage sensor to the hybrid vehicle control ECU is securely connected with no deformation, and that there is no contamination by water or foreign matter.

HINT:

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

For vehicles in which the intermediate connector is inside the relay block, check for signs of water intrusion inside the relay block.

OK:

- The connector is connected securely.

- The terminals are not deformed and are connected securely.

- No water or foreign matter in the connectors.

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
B

CONNECT SECURELY
C

REPAIR OR REPLACE HARNESS OR CONNECTOR
A

4.

CHECK BATTERY VOLTAGE SENSOR (IGCT VOLTAGE)

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 ignition switch to ON (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Remove the No. 1 hybrid battery exhaust duct.

Click here 2020 MY RAV4 HV [06/2020 - 08/2020]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+ 2021 MY RAV4 HV [08/2020 - 12/2021]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+ 2022 MY RAV4 HV [12/2021 - 10/2022]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+ 2023 MY RAV4 HV [10/2022 - 10/2023]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+ 2024 MY RAV4 HV [10/2023 -        ]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+

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

(d) Turn the ignition switch to ON.

(e) for TMMC Made:

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

N17-1 (IGCT) - N17-5 (GND)

Ignition switch ON

11 to 14 V

NOTICE:

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 voltage sensor power source circuit, inspect the following even if the measured voltage is as specified:

  • Installation condition of fuse(s) (before removing fuse(s)) (IGCT circuit)
  • Fuse condition (before and after removing fuse(s)) (IGCT circuit)
  • Connection condition of connectors (IGCT circuit)
  • Wire harness condition (IGCT circuit)
  • Wire harness condition (GND circuit)

*A

for TMMC Made

*a

Component with harness connected

(Battery Voltage Sensor)

(f) for TMC Made:

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

N72-1 (IGCT) - N72-5 (GND)

Ignition switch ON

11 to 14 V

NOTICE:

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 voltage sensor power source circuit, inspect the following even if the measured voltage is as specified:

  • Installation condition of fuse(s) (before removing fuse(s)) (IGCT circuit)
  • Fuse condition (before and after removing fuse(s)) (IGCT circuit)
  • Connection condition of connectors (IGCT circuit)
  • Wire harness condition (IGCT circuit)
  • Wire harness condition (GND circuit)

*A

for TMC Made

*a

Component with harness connected

(Battery Voltage Sensor)

(g) Turn the ignition switch off.

(h) Disconnect the cable from the negative (-) auxiliary battery terminal.

(i) Install the No. 1 hybrid battery exhaust duct.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY VOLTAGE SENSOR POWER SOURCE CIRCUIT)
OK

5.

CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU ASSEMBLY - BATTERY VOLTAGE SENSOR)

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 ignition switch to ON (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect the A31 hybrid vehicle control ECU assembly connector.

NOTICE:

  • 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 voltage sensor is not loose or disconnected.

(c) Remove the No. 1 hybrid battery exhaust duct.

Click here 2020 MY RAV4 HV [06/2020 - 08/2020]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+ 2021 MY RAV4 HV [08/2020 - 12/2021]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+ 2022 MY RAV4 HV [12/2021 - 10/2022]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+ 2023 MY RAV4 HV [10/2022 - 10/2023]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+ 2024 MY RAV4 HV [10/2023 -        ]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+

(d) Disconnect the N17*1, N72*2 battery voltage sensor connector.

NOTICE:

  • Before disconnecting the connector, check that it is not loose or disconnected.
  • Check the terminals of the connector for deformation and corrosion.
  • *1: for TMMC Made
  • *2: for TMC Made

(e) for TMMC Made:

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A31-41 (BTH+) - N17-2 (BTH+)

Ignition switch off

Below 1 Ω

A31-42 (BTH-) - N17-3 (BTH-)

Ignition switch off

Below 1 Ω

N17-2 (BTH+) - Other terminals and body ground

Ignition switch off

10 kΩ or higher

N17-3 (BTH-) - Other terminals and body ground

Ignition switch off

10 kΩ or higher

NOTICE:

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

*A

for TMMC Made

*a

Front view of wire harness connector

(to Hybrid Vehicle Control ECU Assembly)

*b

Rear view of wire harness connector

(to Battery Voltage Sensor)

(f) for TMC Made:

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A31-41 (BTH+) - N72-2 (BTH+)

Ignition switch off

Below 1 Ω

A31-42 (BTH-) - N72-3 (BTH-)

Ignition switch off

Below 1 Ω

N72-2 (BTH+) - Other terminals and body ground

Ignition switch off

10 kΩ or higher

N72-3 (BTH-) - Other terminals and body ground

Ignition switch off

10 kΩ or higher

NOTICE:

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

*A

for TMC Made

*a

Front view of wire harness connector

(to Hybrid Vehicle Control ECU Assembly)

*b

Rear view of wire harness connector

(to Battery Voltage Sensor)

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

(h) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A31-41 (BTH+) - Body ground

Ignition switch ON

Below 1 V

A31-42 (BTH-) - Body ground

Ignition switch ON

Below 1 V

NOTICE:

  • 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.
  • If the ignition switch is turned to ON with the connectors disconnected, other DTCs will be stored. Be sure to clear the DTCs after the inspection.

(j) Turn the ignition switch off.

(k) Disconnect the cable from the negative (-) auxiliary battery terminal.

(l) Reconnect the N17*1, N72*2 battery voltage sensor connector.

  • *1: for TMMC Made
  • *2: for TMC Made

(m) Install the No. 1 hybrid battery exhaust duct.

(n) Reconnect the A31 hybrid vehicle control ECU assembly connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

6.

CHECK HYBRID VEHICLE CONTROL ECU 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 ignition switch to ON (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Remove the No. 1 hybrid battery exhaust duct.

Click here 2020 MY RAV4 HV [06/2020 - 08/2020]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+ 2021 MY RAV4 HV [08/2020 - 12/2021]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+ 2022 MY RAV4 HV [12/2021 - 10/2022]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+ 2023 MY RAV4 HV [10/2022 - 10/2023]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+ 2024 MY RAV4 HV [10/2023 -        ]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL+

(c) Disconnect the N17*1, N72*2 battery voltage sensor connector.

NOTICE:

Before disconnecting the connector, check that it is not loose or disconnected.

  • *1: for TMMC Made
  • *2: for TMC Made

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

(e) Turn the ignition switch to ON.

(f) for TMMC Made:

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

N17-2 (BTH+) - N17-5 (GND)

Ignition switch ON

2.3 to 2.7 V

N17-3 (BTH-) - N17-5 (GND)

Ignition switch ON

2.3 to 2.7 V

NOTICE:

  • 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.
  • If the ignition switch is turned to ON with the connectors disconnected, other DTCs will be stored. Be sure to clear the DTCs after the inspection.

*A

for TMMC Made

*a

Rear view of wire harness connector

(to Battery Voltage Sensor)

(g) for TMC Made:

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

N72-2 (BTH+) - N72-5 (GND)

Ignition switch ON

2.3 to 2.7 V

N72-3 (BTH-) - N72-5 (GND)

Ignition switch ON

2.3 to 2.7 V

NOTICE:

  • 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.
  • If the ignition switch is turned to ON with the connectors disconnected, other DTCs will be stored. Be sure to clear the DTCs after the inspection.

*A

for TMC Made

*a

Rear view of wire harness connector

(to Battery Voltage Sensor)

(h) Turn the ignition switch off.

(i) Disconnect the cable from the negative (-) auxiliary battery terminal.

(j) for TMMC Made:

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

N17-2 (BTH+) - N17-3 (BTH-)

Ignition switch off

4.4 to 5.4 kΩ

HINT:

The resistance will be 2.0 kΩ or less if there is an internal short in the hybrid vehicle control ECU assembly.

(k) for TMC Made:

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

N72-2 (BTH+) - N72-3 (BTH-)

Ignition switch off

4.4 to 5.4 kΩ

HINT:

The resistance will be 2.0 kΩ or less if there is an internal short in the hybrid vehicle control ECU assembly.

(l) Reconnect the N17*1, N72*2 battery voltage sensor connector.

  • *1: for TMMC Made
  • *2: for TMC Made

(m) Install the No. 1 hybrid battery exhaust duct.

OK

REPLACE BATTERY VOLTAGE SENSOR 2020 MY RAV4 HV [10/2019 - 08/2020]; HYBRID / BATTERY CONTROL: BATTERY VOLTAGE SENSOR: REMOVAL 2021 MY RAV4 HV [08/2020 - 12/2021]; HYBRID / BATTERY CONTROL: BATTERY VOLTAGE SENSOR: REMOVAL 2022 MY RAV4 HV [12/2021 - 10/2022]; HYBRID / BATTERY CONTROL: BATTERY VOLTAGE SENSOR: REMOVAL 2023 MY RAV4 HV [10/2022 - 10/2023]; HYBRID / BATTERY CONTROL: BATTERY VOLTAGE SENSOR: REMOVAL 2024 MY RAV4 HV [10/2023 -        ]; HYBRID / BATTERY CONTROL: BATTERY VOLTAGE SENSOR: REMOVAL

NG

REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY 2020 MY RAV4 HV [10/2019 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID VEHICLE CONTROL ECU: REMOVAL 2021 MY RAV4 HV [08/2020 - 12/2021]; HYBRID / BATTERY CONTROL: HYBRID VEHICLE CONTROL ECU: REMOVAL 2022 MY RAV4 HV [12/2021 - 10/2022]; HYBRID / BATTERY CONTROL: HYBRID VEHICLE CONTROL ECU: REMOVAL 2023 MY RAV4 HV [10/2022 - 10/2023]; HYBRID / BATTERY CONTROL: HYBRID VEHICLE CONTROL ECU: REMOVAL 2024 MY RAV4 HV [10/2023 -        ]; HYBRID / BATTERY CONTROL: HYBRID VEHICLE CONTROL ECU: REMOVAL