Toyota Tacoma (2015-2018) Service Manual: Low Beam Headlight Circuit
DESCRIPTION
The main body ECU (multiplex network body ECU) controls the low beam headlights.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
- Inspect the fuses for circuits related to this system before performing the following inspection procedure.
- If the main body ECU (multiplex network body ECU) is replaced, refer
to Registration (See page
.gif)
).*1
- *1: w/ Smart Key System
PROCEDURE
|
1. |
PERFORM ACTIVE TEST USING TECHSTREAM (HEADLIGHT RELAY) |
(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 / Main Body / Active Test.
(e) Perform the Active Test according to the display on the Techstream.
Main Body|
Tester Display |
Test Part |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
Headlight Relay |
Headlight relays |
ON/OFF |
- |
OK:
Headlight relays operate. (Low beam headlights illuminate.)
| OK | .gif) |
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
|
.gif)
|
2. |
INSPECT H-LP LO RELAY |
|
(a) Remove the H-LP LO relay from the engine room relay block. |
|
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(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
3 - 5 |
Voltage is not applied between terminals 1 and 2 |
10 kΩ or higher |
|
3 - 5 |
Voltage is applied between terminals 1 and 2 |
Below 1 Ω |
| NG | |
REPLACE H-LP LO RELAY |
|
|
3. |
CHECK HARNESS AND CONNECTOR (BATTERY - H-LP LO RELAY) |
(a) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
Relay terminal 2 - Body ground |
Always |
11 to 14 V |
|
Relay terminal 5 - Body ground |
Always |
11 to 14 V |
| NG | |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
4. |
CHECK HARNESS AND CONNECTOR (H-LP LO RELAY - DRIVER SIDE JUNCTION BLOCK) |
(a) Disconnect the 1F driver side junction block connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
Relay terminal 1 - 1F-28 |
Always |
Below 1 Ω |
|
1F-28 - Body ground |
Always |
10 kΩ or higher |
| NG | |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
5. |
INSPECT DRIVER SIDE JUNCTION BLOCK |
|
(a) Remove 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 |
|---|---|---|
|
1F-28 - MB-15 (HRLY) |
Always |
Below 1 Ω |
|
1F-28 - Body ground |
Always |
10 kΩ or higher |
|
*a |
Component without harness connected (Driver Side Junction Block) |
| OK | |
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) |
| NG | |
REPLACE DRIVER SIDE JUNCTION BLOCK |
High Beam Headlight Circuit
DESCRIPTION
The main body ECU (multiplex network body ECU) controls the high beam headlights.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Inspect the fuses for circuits related to th ...
Personal Light Assembly
Components
COMPONENTS
ILLUSTRATION
Installation
INSTALLATION
PROCEDURE
1. INSTALL MAP LIGHT BULB
(a) Install the 2 map light bulbs to the 2 map light sockets.
(b) Turn the 2 m ...
Other materials:
Do-it-yourself service precautions
If you perform maintenance yourself, be sure to follow the correct procedures
as given in these sections.
CAUTION
The engine compartment contains many mechanisms and fluids that may move suddenly,
become hot, or become electrically energized. To avoid death or serious injury observe
the ...
Data List / Active Test
DATA LIST / ACTIVE TEST
DATA LIST
HINT:
Using the Techstream to read the Data List allows the values or states of switches,
sensors, actuators and other items to be read without removing any parts. This non-intrusive
inspection can be very useful because intermittent conditions or signals may ...
Main Body ECU Vehicle Information Reading/Writing Process Malfunction (B15F6)
DESCRIPTION
This DTC is stored when items controlled by the main body ECU cannot be customized
via the navigation system vehicle customization screen.
HINT:
The main body ECU controls the items for the following systems that are customizable
via the navigation receiver assembly screen:
...
