Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Compressor Lock Sensor Circuit (B1422/22)

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Vehicle Interior / Heating / Air Conditioning / Air Conditioning System / Compressor Lock Sensor Circuit (B1422/22)

DESCRIPTION

The ECM sends the engine speed signal to the air conditioning amplifier assembly via CAN communication.

The air conditioning amplifier assembly reads the difference between compressor speed and engine speed. When the difference becomes too large, the air conditioning amplifier assembly determines that the compressor is locked, and turns the magnetic clutch assembly off.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

B1422/22

Compressor Lock Sensor Circuit

Open or short in A/C lock sensor circuit
  • Magnetic clutch assembly
  • Cooler compressor assembly
  • Harness or connector between cooler compressor assembly and air conditioning amplifier assembly
  • Air conditioning amplifier assembly

Memorized

(3 sec. or more)*
  • *: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.

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

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.

PERFORM ACTIVE TEST USING TECHSTREAM

(a) Disconnect the magnetic clutch assembly connector.

(b) Install SST to the connector on the magnetic clutch relay side.

SST: 09843-18040

(c) Connect the Techstream to the DLC3.

(d) Start the engine.

(e) Turn the Techstream on.

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

Body Electrical > Air Conditioner > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Magnetic Clutch Relay

Air conditioning system operation

OFF, ON

-

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

1 - Body ground
  • Engine is running
  • Active Test above is being performed

11 to 14 V

HINT:

When performing the Active Test, voltage between 11 and 14 V is output for approximately 3 seconds.

*a

Front view of wire harness connector

(to Magnetic Clutch Assembly)
NG

GO TO AIR CONDITIONING COMPRESSOR MAGNETIC CLUTCH CIRCUIT

OK

3.

INSPECT MAGNETIC CLUTCH ASSEMBLY

(a) Connect the magnetic clutch assembly connector.

(b) Disconnect the D13 cooler compressor assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

3 (MG+) - Body ground

20°C (68°F)

3.8 to 4.2 Ω

*a

Component without harness connected

(Magnetic Clutch Assembly)

(d) Connect a positive (+) lead from the battery to terminal 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.

NG

REPLACE MAGNETIC CLUTCH ASSEMBLY

OK

4.

INSPECT COOLER COMPRESSOR ASSEMBLY

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

1 (SSR+) - 2 (SSR-)

20°C (68°F)

160 to 320 Ω

*a

Component without harness connected

(Magnetic Clutch Assembly)
NG

REPLACE COOLER COMPRESSOR ASSEMBLY

OK

5.

CHECK HARNESS AND CONNECTOR (COOLER COMPRESSOR ASSEMBLY - 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

D13-1 (SSR+) - J42-21 (LOCK)

Always

Below 1 Ω

D13-2 (SSR-) - J42-2 (SG-2)

Always

Below 1 Ω

J42-21 (LOCK) or D13-1 (SSR+) - Body ground

Always

10 kΩ or higher

J42-2 (SG-2) or D13-2 (SSR-) - Body ground

Always

10 kΩ or higher
Result

Proceed to

NG

A

OK (When troubleshooting according to Problem Symptoms Table)

B

OK (When troubleshooting according to the DTC)

C
A

REPAIR OR REPLACE HARNESS OR CONNECTOR
B

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

C

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

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