Air Conditioning System Ig Power Source Circuit

Heater & Air Conditioning System. Lexus Is250, Is220D. Gse20 Ale20
Air Conditioning. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT FUSE (ECU-IG LH)

INSPECT AIR CONDITIONING AMPLIFIER (IG+ - GND)

CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BATTERY)

CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BODY GROUND)

AIR CONDITIONING SYSTEM - IG Power Source Circuit


DESCRIPTION

The main power source is supplied to the A/C amplifier when the engine switch on (IG).
The power source is used for operating the A/C amplifier and servo motor, etc.

WIRING DIAGRAM


Lexus Is250, Is220D. Gse20 Ale20.Air Conditioning.Air Conditioning System.Air Conditioning System Ig Power Source Circuit


INSPECTION PROCEDURE

HINT:
Start the engine before inspection. Check the IG1 relay or battery if the engine does not start.
1.INSPECT FUSE (ECU-IG LH)


    Lexus Is250, Is220D. Gse20 Ale20.Air Conditioning.Air Conditioning System.Air Conditioning System Ig Power Source Circuit

  1. Remove the ECU-IG LH fuse from the cowl side junction block LH.

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

    Standard resistance:
    Tester Item
    		Condition
    		Specified Condition
    ECU-IG LH fuse
    		Always
    		Below 1 Ω


NG
REPLACE FUSE (ECU-IG LH)
OK


2.INSPECT AIR CONDITIONING AMPLIFIER (IG+ - GND)


    Lexus Is250, Is220D. Gse20 Ale20.Air Conditioning.Air Conditioning System.Air Conditioning System Ig Power Source Circuit

  1. Remove the A/C amplifier with its connectors still connected.

  1. Turn the engine switch on (IG).

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

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    J58-21 (IG+) - J58-20 (GND)
    		Engine switch on (IG)
    		10 to 14 V


NG
Go to step 3
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

3.CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BATTERY)


    Lexus Is250, Is220D. Gse20 Ale20.Air Conditioning.Air Conditioning System.Air Conditioning System Ig Power Source Circuit

  1. Disconnect the A/C amplifier connector.

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

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    J58-21 (IG+) - Body ground
    		Engine switch off
    		Below 1 V
    Engine switch on (IG)
    		10 to 14 V


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BODY GROUND)


    Lexus Is250, Is220D. Gse20 Ale20.Air Conditioning.Air Conditioning System.Air Conditioning System Ig Power Source Circuit

  1. Disconnect the A/C amplifier connector.

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

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    J58-20 (GND) - Body ground
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE AIR CONDITIONING AMPLIFIER