Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Air Conditioning Compressor Magnetic Clutch Circuit

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Vehicle Interior / Heating / Air Conditioning / Air Conditioning System / Air Conditioning Compressor Magnetic Clutch Circuit

DESCRIPTION

When the air conditioning amplifier assembly is turned on, a magnetic clutch on signal is sent from the MGC terminal of the air conditioning amplifier assembly. Then, the semiconductor pwr integration ECU turns on to operate the magnetic clutch assembly.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • ECM malfunctions can affect the storage of this DTC. Therefore, check all SFI system DTCs and confirm that the system is normal before performing the following inspection.

    Click here

  • Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.

CHECK CAN COMMUNICATION SYSTEM

(a) Using the Techstream, check if the CAN communication system is functioning normally.

Click here

Result

Proceed to

CAN communication system DTCs are not output

A

CAN communication system DTCs are output

B
B

GO TO CAN COMMUNICATION SYSTEM

A

2.

CHECK SEMICONDUCTOR POWER INTEGRATION ECU

(a) Using a voltmeter, check the signal reading of the semiconductor pwr integration ECU.

Click here

OK:

A normal signal reading is output.

NG

CHECK SEMICONDUCTOR POWER INTEGRATION ECU (RESULT OF SIGNAL READING)

OK

3.

CHECK HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - POWER SOURCE AND BODY GROUND)

(a) Remove the semiconductor pwr integration ECU from the engine room relay block and junction block assembly.

Click here

*a

Component without Semiconductor Pwr Integration ECU

(Engine Room Relay Block and Junction Block Assembly)

-

-

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

2A-1 (ALT) - Body ground

Always

11 to 14 V

1A-1 (BATT) - Body ground

Always

11 to 14 V

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

1D-14 (GND1) - Body ground

Always

Below 1 Ω

1G-5 (GND2) - Body ground

Always

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

CHECK HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - COOLER COMPRESSOR ASSEMBLY)

(a) Disconnect the D13 cooler compressor assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

1D-12 (L) - D13-3 (MG+)

Always

Below 1 Ω

1D-12 (L) or D13-3 (MG+) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

CHECK HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - AIR CONDITIONING AMPLIFIER ASSEMBLY)

(a) Disconnect the J42 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

1D-4 (-S) - J42-9 (MGC)

Always

Below 1 Ω

1D-4 (-S) or J42-9 (MGC) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

6.

CHECK MAGNETIC CLUTCH ASSEMBLY

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

D13-3 (MG+) - Body ground

20°C (68°F)

3.8 to 4.2 Ω

*a

Component without harness connected

(Cooler Compressor Assembly)

(b) Connect a positive (+) lead from the battery to terminal D13-3 (MG+) and check that the following occurs: 1) the magnetic clutch assembly operating sound can be heard, and 2) the magnetic clutch hub and rotor lock.

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

REPLACE MAGNETIC CLUTCH ASSEMBLY

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