Toyota Tundra Service Manual: ECU Power Source Circuit

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

DESCRIPTION

This circuit provides power to operate the air conditioning amplifier.

WIRING DIAGRAM

PROCEDURE

1.

INSPECT FUSE (ECU-B NO.2)

(a) Remove the ECU-B NO.2 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-B NO.2 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

Condition

Specified Condition

J19-21 (B) - Body ground

Always

11 to 14 V
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
    Dtc Check / Clear

    How To Proceed With Troubleshooting

    See More:

    Toyota Tundra Service Manual > Ignition Key Cylinder Light: Inspection
    INSPECTION PROCEDURE 1. INSPECT TRANSPONDER KEY COIL (IGNITION KEY CYLINDER LIGHT) (a) Apply battery voltage to the connector and check the light illumination condition. OK: Condition Specified Condition Battery positive (+) → Terminal 2 (ILL+) Battery negative (-) → Terminal 4 (ILL-) Illuminate ...

    Toyota Tundra Owners Manual

    Toyota Tundra Service Manual

    © 2026 Copyright www.ttundra.com
    0.0235