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
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 | .gif) |
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
|
.gif)
|
2. |
INSPECT PTC HTR RELAY |
(a) Remove the PTC HTR relays.
(b) Inspect the PTC HTR relays (See page .gif)
).
| NG | |
REPLACE PTC HTR RELAY |
|
|
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 |
|
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 |
|
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 |
|
|
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 |
|
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 |
|
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 |
|
|
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 |
|
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 |
|
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 |
|
|
6. |
INSPECT QUICK HEATER ASSEMBLY |
(a) Remove 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:
Installation
INSTALLATION
PROCEDURE
1. INSTALL AIR CONDITIONING UNIT ASSEMBLY
(a) Temporary install the air conditioning unit assembly.
(b) Insert the bracket hook into the holes of the reinforcement bracket, and
temporary install the instrument panel reinforcement assembly.
(c) Install the instrument p ...
Brake
General Maintenance
GENERAL MAINTENANCE
PROCEDURE
1. INSPECT BRAKE LINE PIPES AND HOSES
HINT:
Work in a well-lighted area. Turn the front wheels fully to the right or left
before beginning.
(a) Check all the brake lines and hoses for:
Damage
Wear
Deformation
Cracks
...
Steering Angle Sensor (C1A47)
DESCRIPTION
The forward recognition camera receives steering angle information from the spiral
cable with sensor sub-assembly. If the forward recognition camera detects a spiral
cable with sensor sub-assembly malfunction, DTC C1A47 is stored.
DTC No.
Detection Item
...
