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 > Sfi System: Check For Intermittent Problems
    CHECK FOR INTERMITTENT PROBLEMS HINT: Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect with the Techstream when the ECM is in check mode. In check mode, the ECM uses 1 trip detection logic, which is more sensitive to malfunctions than normal mode (default), whic ...

    Toyota Tundra Owners Manual

    Toyota Tundra Service Manual

    © 2026 Copyright www.ttundra.com
    0.0196