Toyota Tacoma (2015-2018) Service Manual: ECU Power Source Circuit

Toyota Tacoma (2015-2018) Service Manual / Tire And Wheel / Tire Pressure Warning System / ECU Power Source Circuit

DESCRIPTION

The IG circuit is the power source for the tire pressure warning ECU and receiver.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When replacing the tire pressure warning ECU and receiver, read the transmitter IDs stored in the old ECU using the Techstream and write them down before removal.
It is necessary to perform initialization (See page ) after registration (See page ) of the transmitter IDs into the tire pressure warning ECU and receiver if the ECU has been replaced.

HINT:

Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (ECU - BATTERY AND BODYGROUND)

(a) Disconnect the T14*1, T25*2, T24*3 tire pressure warning ECU and receiver connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
T14-1 (IG) - Body ground1 T25-1 (IG) - Body ground2 T24-1 (IG) - Body ground*3	Ignition switch ON	10 to 16 V
Ignition switch off	Below 1 V

Tester Connection

Switch Condition

Specified Condition

T14-1 (IG) - Body ground*1

T25-1 (IG) - Body ground*2

T24-1 (IG) - Body ground*3

Ignition switch ON

10 to 16 V

Ignition switch off

Below 1 V

Standard Resistance:

Tester Connection	Condition	Specified Condition
T14-12 (GND) - Body ground1 T25-12 (GND) - Body ground2 T24-12 (GND) - Body ground*3	Always	Below 1 Ω

Tester Connection

Condition

Specified Condition

T14-12 (GND) - Body ground*1

T25-12 (GND) - Body ground*2

T24-12 (GND) - Body ground*3

Always

Below 1 Ω

Text in Illustration

*a	Front view of wire harness connector (to Tire Pressure Warning ECU and Receiver)

*1: w/o Wireless Door Lock System
*2: w/o Smart Key System with Wireless Door Lock System
*3: w/ Smart Key System

REPLACE TIRE PRESSURE WARNING ECU AND RECEIVER

REPAIR OR REPLACE HARNESS OR CONNECTOR

No Signal from Transmitter ID1 (C2121/21-C2124/24,C2181/81-C2184/84)

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