HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): B1477; A/C Inverter Low Voltage Power Resource System; 2020 - 2022 MY Corolla Corolla HV [01/2019

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM100000001H97J
Model Year Start: 2020	Model: Corolla	Prod Date Range: [01/2019 - 09/2022]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): B1477; A/C Inverter Low Voltage Power Resource System; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

DTC

B1477

A/C Inverter Low Voltage Power Resource System

DESCRIPTION

The compressor with motor assembly monitors the inverter control power source voltage. The hybrid vehicle control ECU stops the compressor control and stores this DTC if 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
B1477	A/C Inverter Low Voltage Power Resource System	Open or short to ground in inverter control power voltage circuit	Compressor with motor assembly	Memorized

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:

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.
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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.
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PROCEDURE

1.	REPLACE COMPRESSOR WITH MOTOR ASSEMBLY

(a) Replace the compressor with motor assembly.

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NOTICE:

As this DTC is stored when the compressor with motor assembly is malfunctioning, it is necessary to replace the compressor with motor assembly.

END