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 > Sfi System: Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 2) (P0037,P0038,P0057,P0058,P0141,P0161,P102D,P105D)
DESCRIPTION Refer to DTC P0136 (See page ). HINT: When any of these DTCs are stored, the ECM enters fail-safe mode. The ECM turns off the Heated Oxygen (HO2) sensor heater in fail-safe mode. Fail-safe mode continues until the ignition switch is turned off. The ECM provides a pulse width modulated co ...

Toyota Tundra Owners Manual