Toyota Tundra Service Manual: IG Power Source Circuit

Toyota Tundra Service Manual / Vehicle Interior / Air Conditioning / Air Conditioning System(for Manual Air Conditioning System) / IG Power Source Circuit

DESCRIPTION

When the ignition switch is turned ON, positive (+) battery voltage is applied to the air conditioning amplifier.

WIRING DIAGRAM

PROCEDURE

1.

INSPECT FUSE (ECU-IG1 NO.3)

(a) Remove the ECU-IG1 NO.3 fuse from the driver side junction block.

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

Standard resistance:

Tester Connection

Condition

Specified Condition

ECU-IG1 NO.3 fuse

Always

Below 1 Ω
NG

REPLACE FUSE
OK

2.

CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BATTERY AND BODY GROUND)

(a) Disconnect the J19 air conditioning amplifier connector.

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

Standard resistance:

Tester Connection

Condition

Specified Condition

J19-14 (GND) - Body ground

Always

Below 1 Ω

Standard voltage:

Tester Connection

Switch Condition

Specified Condition

J19-1 (IG+) - Body ground

Ignition switch ON

11 to 14 V
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
    How To Proceed With Troubleshooting

    Parts Location

    See More:

    Toyota Tundra Service Manual > 4wd Control Switch: Removal
    REMOVAL PROCEDURE 1. REMOVE CENTER INSTRUMENT CLUSTER FINISH PANEL SUB-ASSEMBLY for Column Shift Type: (See page ) for Floor Shift Type: (See page ) 2. REMOVE TRANSFER POSITION SWITCH (a) Detach the 2 claws to remove the transfer position switch. ...

    Toyota Tundra Owners Manual

    Toyota Tundra Service Manual

    © 2026 Copyright www.ttundra.com
    0.0315