HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model with Automatic Air Conditioning System): B1451; Compressor Solenoid Circuit; 2020 - 2022 MY Corolla Corolla Hatchback GR Corolla [01/2019

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM100000001HBSQ
Model Year Start: 2020	Model: GR Corolla	Prod Date Range: [01/2019 - 09/2022]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model with Automatic Air Conditioning System): B1451; Compressor Solenoid Circuit; 2020 - 2022 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 09/2022]

DTC

B1451

Compressor Solenoid Circuit

DESCRIPTION

In this circuit, the compressor assembly with pulley receives refrigerant compression demand signals from the air conditioning amplifier assembly.

Based on this signal, the compressor assembly with pulley changes the amount of compressor output.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Memory
B1451	Compressor Solenoid Circuit	Open or short in compressor solenoid circuit	Compressor assembly with pulley Harness or connector Air conditioning amplifier assembly	-

1.	CHECK HARNESS AND CONNECTOR (COMPRESSOR ASSEMBLY WITH PULLEY - AIR CONDITIONING AMPLIFIER ASSEMBLY)

(a) Disconnect the I49 air conditioning amplifier assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
C85-2 (SOL+) - I49-18 (SOL+)	Always	Below 1 Ω
C85-2 (SOL+) or I49-18 (SOL+) - Other terminals and body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

2.	INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

*a	Front view of wire harness connector (to Compressor Assembly with Pulley)

(a) Disconnect the C85 compressor assembly with pulley connector.

(b) Check the waveform.

Item	Content
Terminal No.	C85-2 (SOL+) - Body ground
Tool Setting	5 V/DIV., 500 μs./DIV.
Condition	Engine running Blower switch: LO A/C switch: On

OK:

Waveform is similar to that shown in the illustration.

REPLACE COMPRESSOR ASSEMBLY WITH PULLEY

for M20A-FKS: Click here

for 2ZR-FAE: Click here