Last Modified: 7-3-2017 6.8:8.0.40 Doc ID: RM0000018ND005X
Model Year Start: 2007 Model: LX470 Prod Date Range: [08/2006 -           ]
Title: AIR CONDITIONING: AIR CONDITIONING SYSTEM: Back-up Power Source Circuit; 2007 MY LX470 [08/2006 -        ]

Back-up Power Source Circuit

DESCRIPTION

This is the back-up power source for the A/C amplifier. Power is supplied even when the ignition switch is OFF and is used for diagnostic trouble code memory, etc.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1.

INSPECT FUSE

(a) Remove the ECU-B2 fuse from the cowl side junction block RH.

(b) Measure the resistance of the fuse.

Standard resistance:

Below 1 Ω

OK

REPLACE FUSE

NG

2.

CHECK WIRE HARNESS AND CONNECTOR

(a) Disconnect the A49 A/C amplifier connector.

(b) Measure the voltage and resistance of the wire harness side connector.

Standard voltage:

Tester Connection

Condition

Specified Condition

+B (A49-11) - GND (A49-12)

Always

10 to 14 V

Standard resistance:

Tester Connection

Specified Condition

+B (A49-11) - Body ground

10 kΩ or higher

GND (A49-12) - Body ground

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

REPLACE AIR CONDITIONING AMPLIFIER