Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001A3OR
Model Year Start: 2019 Model: Avalon HV Prod Date Range: [04/2018 -           ]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): B1471; A/C Inverter High Voltage Power Resource System; 2019 - 2022 MY Avalon HV [04/2018 -        ]

DTC

B1471

A/C Inverter High Voltage Power Resource System

DESCRIPTION

The hybrid vehicle control ECU assembly monitors the voltage of the HV battery. The hybrid vehicle control ECU assembly stops compressor control and stores this DTC when the monitored voltage is outside the specified range.

This DTC will be stored as a history DTC. Compressor control may not resume unless the power switch is turned off.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

B1471

A/C Inverter High Voltage Power Resource System

  • Open or short in A/C inverter high voltage power resource system
  • Boost inverter malfunctioning
  • HV air conditioning wire
  • Compressor with motor assembly
  • Hybrid control system

Memorized

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION:

  • Before inspecting the high-voltage system, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
  • Do not touch the high-voltage connectors or terminals for 10 minutes after the service plug grip is removed.

NOTICE:

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • 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 - 2022 MY Avalon Avalon HV [04/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: PRECAUTION

  • The hybrid control system and air conditioning system output DTCs separately. Perform troubleshooting for the hybrid control system first if DTCs for both systems are output simultaneously.
  • The air conditioning system uses the CAN communication system. Inspect the communication functions by following How to Proceed with Troubleshooting. Troubleshoot the air conditioning system after confirming that the communication systems are functioning properly.

    Click here 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): HOW TO PROCEED WITH TROUBLESHOOTING 2021 - 2022 MY Avalon HV [08/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): HOW TO PROCEED WITH TROUBLESHOOTING

PROCEDURE

1.

CHECK FOR DTC

(a) Check if hybrid control system DTCs are output.

Powertrain > Hybrid Control > Trouble Codes

Result

Proceed to

DTCs are not output

A

DTCs are output

B

B

GO TO HYBRID CONTROL SYSTEM 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): HOW TO PROCEED WITH TROUBLESHOOTING 2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY): HOW TO PROCEED WITH TROUBLESHOOTING

A

2.

INSPECT HV AIR CONDITIONING WIRE

CAUTION:

Be sure to wear insulated gloves.

(a) Disconnect the T1 and T2 HV air conditioning wire connectors.

HINT:

Click here 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: INVERTER WITH CONVERTER: REMOVAL 2021 MY Avalon HV [08/2020 - 08/2021]; HYBRID / BATTERY CONTROL: INVERTER WITH CONVERTER: REMOVAL 2022 MY Avalon HV [08/2021 -        ]; HYBRID / BATTERY CONTROL: INVERTER WITH CONVERTER: REMOVAL

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

T1-2 (PB) - T2-1 (ACPB)

Always

Below 1 Ω

NG

GO TO STEP 4

OK

3.

INSPECT HV AIR CONDITIONING WIRE

CAUTION:

Be sure to wear insulated gloves.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

T1-1 (PE) - T2-2 (ACPE)

Always

Below 1 Ω

OK

REPLACE COMPRESSOR WITH MOTOR ASSEMBLY 2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; HEATING / AIR CONDITIONING: COMPRESSOR (for A25A-FXS): REMOVAL 2022 MY Avalon HV [08/2021 -        ]; HEATING / AIR CONDITIONING: COMPRESSOR (for A25A-FXS): REMOVAL

NG

REPLACE HV AIR CONDITIONING WIRE 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: INVERTER WITH CONVERTER: REMOVAL 2021 MY Avalon HV [08/2020 - 08/2021]; HYBRID / BATTERY CONTROL: INVERTER WITH CONVERTER: REMOVAL 2022 MY Avalon HV [08/2021 -        ]; HYBRID / BATTERY CONTROL: INVERTER WITH CONVERTER: REMOVAL

4.

INSPECT HV AIR CONDITIONING WIRE

CAUTION:

Be sure to wear insulated gloves.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

T1-2 (PB) - Body ground

Always

10 kΩ or higher

OK

REPLACE COMPRESSOR WITH MOTOR ASSEMBLY 2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; HEATING / AIR CONDITIONING: COMPRESSOR (for A25A-FXS): REMOVAL 2022 MY Avalon HV [08/2021 -        ]; HEATING / AIR CONDITIONING: COMPRESSOR (for A25A-FXS): REMOVAL

NG

REPLACE HV AIR CONDITIONING WIRE 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: INVERTER WITH CONVERTER: REMOVAL 2021 MY Avalon HV [08/2020 - 08/2021]; HYBRID / BATTERY CONTROL: INVERTER WITH CONVERTER: REMOVAL 2022 MY Avalon HV [08/2021 -        ]; HYBRID / BATTERY CONTROL: INVERTER WITH CONVERTER: REMOVAL