Toyota 4Runner: Back-up Power Source Circuit

Toyota 4Runner Service Manual / Vehicle Interior / Heating / Air Conditioning / Air Conditioning System(for Automatic Air Conditioning System) / Back-up Power Source Circuit

DESCRIPTION

The back-up power source circuit for the air conditioning amplifier assembly is shown below. Power is supplied even after the ignition switch is turned off and is used for diagnostic trouble code memory, etc.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BATTERY)

(a) Disconnect the F42 amplifier connector.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
F42-21 (B) - Body ground	Always	11 to 14 V

Text in Illustration

*a	Rear view of wire harness connector (to Air Conditioning Amplifier Assembly)

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

REPAIR OR REPLACE HARNESS OR CONNECTOR

IG Power Source Circuit

DESCRIPTION The main power source is supplied to the air conditioning amplifier assembly when the ignition switch is turned to ON. The power source is used for operating the air conditioning ampl ...

Air Conditioning System(for Manual Air Conditioning System)

...

Other materials about Toyota 4Runner:

Precaution
PRECAUTION 1. PRECAUTIONS FOR USERS WITH PACEMAKERS (a) Weak electric waves are emitted from the key. If a pacemaker is being used, read the pacemaker instruction manual before using the smart key system. If implanted pacemakers or cardioverter def ...

How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT HINT: Use these procedures to troubleshoot the theft deterrent system. *: Use the Techstream. The troubleshooting procedures for the theft deterrent system are based on the premise that the door lock control sys ...