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 > Meter / Gauge System: Communication with BODY ECU (Receive) (U0142)
    DESCRIPTION The combination meter assembly communicates with the main body ECU (multiplex network body ECU) via the CAN line. DTC Code DTC Detection Condition Trouble Area U0142 When either of following conditions is detected: IG voltage 10.5 V or more No communication with main body ECU (multiplex ...

    Toyota Tundra Owners Manual

    Toyota Tundra Service Manual

    © 2025 Copyright www.ttundra.com
    0.0333