HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): B1473; A/C Inverter Start-up Signal System; 2021 - 2022 MY Corolla Corolla HV [04/2020

Last Modified: 05-13-2024	6.11:8.1.0	Doc ID: RM100000001O7WW
Model Year Start: 2021	Model: Corolla	Prod Date Range: [04/2020 - 09/2022]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): B1473; A/C Inverter Start-up Signal System; 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]

DTC

B1473

A/C Inverter Start-up Signal System

DESCRIPTION

The inverter activation signal is sent to the compressor with motor assembly from the hybrid vehicle control ECU. Compressor control is stopped and this DTC is stored if there is an open or short in the signal circuit.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Memory
B1473	A/C Inverter Start-up Signal System	Open or short in A/C inverter start-up signal circuit	Compressor with motor assembly Hybrid control system Air conditioning amplifier assembly	-

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:

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.	CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

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

(d) Enter the following menus: Body Electrical / Air Conditioner / Trouble Codes.

(e) Check if air conditioning system DTCs are output.

Body Electrical > Air Conditioner > Trouble Codes

Result	Proceed to
Only B1473 is output	A
B1473 and B1498 are output simultaneously	B

GO TO DTC B1498

2.	CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

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

(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

3.	PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

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

(d) Enter the following menus: Body Electrical / Air Conditioner / Active Test.

(e) Perform the Active Test according to the display on the Techstream.

Body Electrical > Air Conditioner > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Compressor Target Speed

Compressor with motor assembly

Min.: 0

Max.: 7500

Body Electrical > Air Conditioner > Active Test

Tester Display
Compressor Target Speed

OK:

Compressor with motor assembly operates normally.

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

REPLACE COMPRESSOR WITH MOTOR ASSEMBLY