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
INSPECTION PROCEDURE
- Start the engine before inspection. Check the IG1 relay or battery if the engine does not start.
| 1.INSPECT FUSE (ECU-IG LH) |
Remove the ECU-IG LH fuse from the cowl side junction block LH.
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 |
| OK | |
| |
| PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE |
|
| 3.CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BATTERY) |
Disconnect the A/C amplifier connector.
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 |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| 4.CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BODY GROUND) |
Disconnect the A/C amplifier connector.
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 |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| OK | |
| |
| REPLACE AIR CONDITIONING AMPLIFIER |
|
LEXUS IS250, IS220d / GSE20 ALE20
