Air Conditioning System - Back-Up Power Source Circuit

Lexus IS250 IS220d GSE20 ALE20 - AIR CONDITIONING

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT FUSE (A/C)

INSPECT AIR CONDITIONING AMPLIFIER (AIR CONDITIONING AMPLIFIER - BODY GROUND)

AIR CONDITIONING SYSTEM - Back-up Power Source Circuit

DESCRIPTION

The back-up power source circuit for the A/C amplifier is shown below. Power is supplied even when turning the engine switch off and is used for diagnostic trouble code memory, etc.


WIRING DIAGRAM

Air Conditioning System - Back-Up Power Source Circuit. AIR CONDITIONING. Lexus IS250 IS220d GSE20 ALE20

INSPECTION PROCEDURE

1.INSPECT FUSE (A/C)
Air Conditioning System - Back-Up Power Source Circuit. AIR CONDITIONING. Lexus IS250 IS220d GSE20 ALE20

Remove the A/C fuse from the cowl side junction block LH.

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

  • Standard resistance:
  • Tester ItemConditionSpecified Condition
    A/C fuseAlwaysBelow 1 Ω
NG
REPLACE FUSE (A/C)
OK
2.INSPECT AIR CONDITIONING AMPLIFIER (AIR CONDITIONING AMPLIFIER - BODY GROUND)
Air Conditioning System - Back-Up Power Source Circuit. AIR CONDITIONING. Lexus IS250 IS220d GSE20 ALE20

Disconnect the A/C amplifier connector.

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

  • Standard voltage:
  • Tester ConnectionConditionSpecified Condition
    J58-1 (B) - Body groundAlways10 to 14 V
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE