Lexus IS250 IS220d GSE20 ALE20 - AIR CONDITIONING

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK MULTIPLEX COMMUNICATION SYSTEM

CHECK CAN COMMUNICATION SYSTEM

READ VALUE OF INTELLIGENT TESTER

READ VALUE OF INTELLIGENT TESTER

PERFORM ACTIVE TEST BY INTELLIGENT TESTER

INSPECT FUSE (A/C COMP)

INSPECT RELAY (A/C COMP)

INSPECT A/C COMPRESSOR

INSPECT MAGNETIC CLUTCH

CHECK WIRE HARNESS (ENGINE ROOM R/B AND J/B NO. 2 - A/C COMPRESSOR)

CHECK WIRE HARNESS (ENGINE ROOM R/B AND J/B NO. 2 - ECM)

REPLACE AIR CONDITIONING AMPLIFIER

AIR CONDITIONING SYSTEM - Air Conditioning Compressor Magnetic Clutch Circuit

DESCRIPTION

The A/C amplifier sends a magnetic clutch ON command signal to the ECM through the BEAN line and CAN line. Then the ECM turns the A/C COMP relay on to turn the magnetic clutch on.


WIRING DIAGRAM

Air Conditioning System - Air Conditioning Compressor Magnetic Clutch Circuit. AIR CONDITIONING. Lexus IS250 IS220d GSE20 ALE20

INSPECTION PROCEDURE

1.CHECK MULTIPLEX COMMUNICATION SYSTEM

Use the intelligent tester to check if the Multiplex Communication System (MPX) is functioning normally.

  • Result:
  • ResultProceed to
    MPX DTC is not outputA
    MPX DTC is outputB
B
Go to step 12
OK
4.READ VALUE OF INTELLIGENT TESTER

Connect the intelligent tester to the DLC3.

Turn the engine switch on (IG) and turn the intelligent tester main switch on.

Change the blower fan speed to LO using the blower switch.

Turn the A/C switch on and off.

Select the item below in the Data List, and read the display on the intelligent tester.

Data List / Engine:
ItemMeasure ItemNormal ConditionDiagnostic Note
A/C Magnetic Clutch Relay
(A/C Magnetic Clutch Relay)		A/C magnetic clutch relay / OFF, ONON: A/C magnetic clutch ON
OFF: A/C magnetic clutch OFF		-
  • OK:
  • The display is as specified in the normal condition.
NG
REPLACE ECM
OK
5.PERFORM ACTIVE TEST BY INTELLIGENT TESTER

Connect the intelligent tester to the DLC3.

Turn the engine switch on (IG) and turn the intelligent tester main switch on.

Select the item below in the Active Test and read the display on the intelligent tester.

Active Test / Engine:
ItemTest Details / Display (Range)Diagnostic Note
Magnetic Clutch Relay
(A/C Mag Clutch)		Magnetic Clutch Relay / OFF, ON-
  • OK:
  • The magnetic clutch operates normally.
OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
NG
6.INSPECT FUSE (A/C COMP)
Air Conditioning System - Air Conditioning Compressor Magnetic Clutch Circuit. AIR CONDITIONING. Lexus IS250 IS220d GSE20 ALE20

Remove the A/C COMP fuse from the engine room R/B and J/B No. 2.

Measure the resistance of the fuse.

  • Standard resistance:
  • Tester ItemConditionSpecified Condition
    A/C COMP fuseAlwaysBelow 1 Ω
NG
REPLACE FUSE (A/C COMP)
OK
7.INSPECT RELAY (A/C COMP)
Air Conditioning System - Air Conditioning Compressor Magnetic Clutch Circuit. AIR CONDITIONING. Lexus IS250 IS220d GSE20 ALE20

Remove the A/C COMP relay from the engine room R/B and J/B No. 2.

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

  • Standard resistance:
  • Tester ConnectionSpecified Condition
    3 - 510 kΩ or higher
    3 - 5Below 1 Ω
    (when battery voltage is applied to terminals 1 and 2)
NG
REPLACE RELAY (A/C COMP)
OK
8.INSPECT A/C COMPRESSOR
Air Conditioning System - Air Conditioning Compressor Magnetic Clutch Circuit. AIR CONDITIONING. Lexus IS250 IS220d GSE20 ALE20

Disconnect the A/C compressor connector.

Disconnect the magnetic clutch connector.

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

  • Standard resistance:
  • Tester ConnectionConditionSpecified Condition
    E8-1 (MG+) - A-1AlwaysBelow 1 Ω
    E8-1 (MG+) - Body groundAlways10 kΩ or higher
NG
REPLACE A/C COMPRESSOR
OK
9.INSPECT MAGNETIC CLUTCH
Air Conditioning System - Air Conditioning Compressor Magnetic Clutch Circuit. AIR CONDITIONING. Lexus IS250 IS220d GSE20 ALE20

Measure the resistance of the connector.

  • Standard resistance:
  • Tester ConnectionConditionSpecified Condition
    A-1 - Body groundAlways3.4 to 3.8 Ω

When connector terminal A1 is connected to the positive (+) battery terminal, check that the following occurs: 1) the magnetic clutch's operating sound can be heard, and 2) the magnetic clutch's hub and rotor lock.

NG
REPLACE MAGNETIC CLUTCH
OK
10.CHECK WIRE HARNESS (ENGINE ROOM R/B AND J/B NO. 2 - A/C COMPRESSOR)
Air Conditioning System - Air Conditioning Compressor Magnetic Clutch Circuit. AIR CONDITIONING. Lexus IS250 IS220d GSE20 ALE20

Turn the engine switch on (IG).

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

  • Standard voltage:
  • Tester ConnectionSpecified Condition
    Relay block A/C COMP relay terminal 5 - Body ground10 to 14 V
    Relay block A/C COMP relay terminal 1 - Body ground10 to 14 V
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
11.CHECK WIRE HARNESS (ENGINE ROOM R/B AND J/B NO. 2 - ECM)
Air Conditioning System - Air Conditioning Compressor Magnetic Clutch Circuit. AIR CONDITIONING. Lexus IS250 IS220d GSE20 ALE20

Disconnect the ECM connector.

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

  • Standard resistance:
  • Tester ConnectionSpecified Condition
    Relay block A/C COMP relay terminal 2 - A6-13 (ACMG)Below 1 Ω
    A6-13 (ACMG) - Body ground10 kΩ or higher
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
REPAIR OR REPLACE HARNESS OR CONNECTOR (A/C COMPRESSOR - ENGINE ROOM R/B AND J/B NO. 2)
12.REPLACE AIR CONDITIONING AMPLIFIER

Replace the A/C amplifier with a normal one and check that the condition returns to normal.

  • OK:
  • Same problem does not occur.
OK
END
NG
REPLACE ECM
LEXUS IS250, IS220d / GSE20 ALE20
AIR CONDITIONING
Lexus IS250 IS220d GSE20 ALE20
AIR CONDITIONING SYSTEM