Toyota Tundra Service Manual: 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

REPLACE FUSE

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

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

REPAIR OR REPLACE HARNESS OR CONNECTOR

Toyota Tundra Service Manual > Touch Select 2-4 And High-low System: Four Wheel Drive (4WD) Low Switch Circuit Range / Performance (P2772)
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Toyota Tundra Owners Manual