Toyota Tacoma manuals

Toyota Tacoma 2015-2018 Service Manual: PTC Heater Circuit

DESCRIPTION

PTC HTR heater relays are closed in accordance with signals from the air conditioning amplifier assembly and power is supplied to the quick heater assembly installed on the radiator heater unit.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION / NOTICE / HINT

NOTICE:

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

PROCEDURE

1.

PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Air Conditioner / Active Test.

(e) Check the operation by referring to the table below.

Air Conditioner

Tester Display

Test Part

Control Range

Diagnostic Note

Heater Active Level

Quick heater assembly

Min.: 0, Max.: 3

-

OK:

Heater Active Level changes normally.

NG

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

OK

2.

INSPECT PTC HTR RELAY

(a) Remove the PTC HTR relays.

(b) Inspect the PTC HTR relays (See page ).

NG

REPLACE PTC HTR RELAY

OK

3.

CHECK HARNESS AND CONNECTOR (PTC HTR RELAY - POWER SOURCE CIRCUIT)

(a) Remove the PTC HTR relays.

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

Standard Voltage:

PTC HTR NO. 1

Tester Connection

Condition

Specified Condition

PTC HTR NO. 1-1 - Body ground

Always

11 to 14 V

PTC HTR NO. 1-5 - Body ground

Always

11 to 14 V

PTC HTR NO. 2

Tester Connection

Condition

Specified Condition

PTC HTR NO. 2-1 - Body ground

Always

11 to 14 V

PTC HTR NO. 2-5 - Body ground

Always

11 to 14 V

PTC HTR NO. 3

Tester Connection

Condition

Specified Condition

PTC HTR NO. 3-1 - Body ground

Always

11 to 14 V

PTC HTR NO. 3-5 - Body ground

Always

11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.

CHECK HARNESS AND CONNECTOR (PTC HTR RELAY - AIR CONDITIONING AMPLIFIER ASSEMBLY)

(a) Remove the PTC HTR relays.

(b) Disconnect the A36 air conditioning amplifier assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

PTC HTR NO. 1

Tester Connection

Condition

Specified Condition

PTC HTR NO. 1-2 - A36-19 (PTC1)

Always

Below 1 Ω

PTC HTR NO. 1-2 or A36-19 (PTC1) - Body ground

Always

10 kΩ or higher

PTC HTR NO. 2

Tester Connection

Condition

Specified Condition

PTC HTR NO. 2-2 - A36-20 (PTC2)

Always

Below 1 Ω

PTC HTR NO. 2-2 or A36-20 (PTC2) - Body ground

Always

10 kΩ or higher

PTC HTR NO. 3

Tester Connection

Condition

Specified Condition

PTC HTR NO. 3-2 - A36-21 (PTC3)

Always

Below 1 Ω

PTC HTR NO. 3-2 or A36-21 (PTC3) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5.

CHECK HARNESS AND CONNECTOR (QUICK HEATER ASSEMBLY - PTC HTR RELAY AND BODY GROUND)

(a) Remove the PTC HTR relays.

(b) Disconnect the Q1 quick heater assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

PTC HTR NO. 1

Tester Connection

Condition

Specified Condition

PTC HTR NO. 1-3 - Q1-3 (B)

Always

Below 1 Ω

Q1-2 (E) - Body ground

Always

Below 1 Ω

Q1-4 (E) - Body ground

Always

Below 1 Ω

PTC HTR NO. 1-3 or Q1-3 (B) - Body ground

Always

10 kΩ or higher

PTC HTR NO. 2

Tester Connection

Condition

Specified Condition

PTC HTR NO. 2-3 - Q1-1 (B)

Always

Below 1 Ω

Q1-2 (E) - Body ground

Always

Below 1 Ω

PTC HTR NO. 2-3 or Q1-1 (B) - Body ground

Always

10 kΩ or higher

PTC HTR NO. 3

Tester Connection

Condition

Specified Condition

PTC HTR NO. 3-3 - Q1-5 (B)

Always

Below 1 Ω

Q1-4 (E) - Body ground

Always

Below 1 Ω

PTC HTR NO. 3-3 or Q1-5 (B) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

6.

INSPECT QUICK HEATER ASSEMBLY

(a) Remove the quick heater assembly (See page (b) Inspect the quick heater assembly (See page ).

(b) Inspect the quick heater assembly (See page ).

OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPLACE QUICK HEATER ASSEMBLY

IG Power Source Circuit
DESCRIPTION The main power source is supplied to the air conditioning amplifier assembly when the ignition switch is turned to ON. The power is used for operating the air conditioning amplifier as ...

Back-up Power Source Circuit
DESCRIPTION The back-up power source circuit for the air conditioning amplifier assembly is shown below. Power is supplied even when the ignition switch is off. The power is used for diagnostic t ...

Other materials:

System Diagram
SYSTEM DIAGRAM Communication Table Sender Receiver Signal Line *1: for Vacuum Brake Booster *2: for Hydraulic Brake Booster Millimeter Wave Radar Sensor Assembly Forward Recognition Camera ...

Inspection
INSPECTION PROCEDURE 1. INSPECT BRAKE DRUM INSIDE DIAMETER (a) Using a brake drum gauge or equivalent, measure the inside diameter of the drum. Standard inside diameter: 254 mm (10.00 in.) Maximum inside diameter: 256 mm (10.08 in.) If the inside diameter is greater than the maximum, r ...

Low Output Signal of Front Speed Sensor RH (Test Mode DTC) (C1271,C1272,C1401,C1402)
DESCRIPTION The speed sensor detects the wheel speed and sends the appropriate signals to the skid control ECU (master cylinder solenoid). These signals are used for brake control. The speed sensor rotors have rows of alternating N and S magnetic poles and their magnetic fields change when t ...

© 2011-2020 Copyright www.ttguide.net