HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): B1471; A/C Inverter High Voltage Power Resource System; 2021 - 2022 MY Corolla Corolla HV [04/2020

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM100000001O7WU
Model Year Start: 2021	Model: Corolla	Prod Date Range: [04/2020 - 09/2022]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): B1471; A/C Inverter High Voltage Power Resource System; 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]

DTC

B1471

A/C Inverter High Voltage Power Resource System

DESCRIPTION

The hybrid vehicle control ECU monitors the voltage of the HV battery. The hybrid vehicle control ECU 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
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

PROCEDURE

1.	CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

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

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

(e) 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

GO TO HYBRID CONTROL SYSTEM

for NICKEL METAL HYDRIDE BATTERY: Click here

for LITHIUM-ION BATTERY: Click here

2.	INSPECT HV AIR CONDITIONING WIRE

CAUTION:

Be sure to wear insulated gloves.

(a) Disconnect the X1 and X2 HV air conditioning wire connectors.

HINT:

Click here

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
X1-2 (PB) - X2-1 (ACPB)	Always	Below 1 Ω

GO TO STEP 4

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
X1-1 (PE) - X2-2 (ACPE)	Always	Below 1 Ω

REPLACE COMPRESSOR WITH MOTOR ASSEMBLY

REPLACE HV AIR CONDITIONING WIRE

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
X1-2 (PB) - Body ground	Always	10 kΩ or higher

REPLACE COMPRESSOR WITH MOTOR ASSEMBLY

REPLACE HV AIR CONDITIONING WIRE