Toyota Tacoma 2015-2018 Service Manual: System Description
SYSTEM DESCRIPTION
1. SEAT BELT WARNING SYSTEM DESCRIPTION
(a) Seat belt warning light operation for driver seat belt:
The seat belt warning light on the combination meter assembly illuminates, blinks or turns off in accordance with the driver seat belt state, vehicle speed, shift lever position and parking brake state.
(b) Seat belt warning light operation for front passenger seat belt:
The seat belt warning light on the combination meter assembly illuminates, blinks or turns off in accordance with whether the front passenger seat is occupied, the front passenger seat belt state, vehicle speed, shift lever position and parking brake state.
(c) Seat belt warning buzzer:
After turning the ignition switch to ON, if the driver seat belt is not fastened within 1.8 seconds, check that the seat belt warning buzzer in the combination meter assembly sounds at an interval of 1.2 seconds for 6 seconds.
When the vehicle is driven at 20 km/h (12 mph) or more with the front passenger seat occupied and the driver or front passenger seat belt not fastened, the seat belt warning buzzer in the combination meter assembly sounds once.
When 24 seconds have passed after the buzzer sounded, the seat belt warning buzzer in the combination meter assembly sounds at an interval of 1.2 seconds for 9.6 seconds.
After that, the seat belt warning buzzer in the combination meter assembly sounds at an interval of 0.4 seconds for 20 seconds.
2. FUNCTION OF MAIN COMPONENTS
|
Component |
Function |
|---|---|
|
Front seat inner belt assembly LH |
Informs the airbag sensor assembly of the driver seat belt condition (fastened or unfastened). |
|
Front seat inner belt assembly RH |
Informs the occupant detection ECU of the front passenger seat belt condition (fastened or unfastened). |
|
Informs the occupant detection ECU of the front passenger seat condition (occupied or unoccupied). |
|
Combination meter assembly |
|
|
Occupant detection ECU |
Sends the front passenger seat belt buckle switch signal and occupant detection signal to the airbag sensor assembly. |
|
Airbag sensor assembly |
|
|
Main body ECU |
Sends the driver seat belt buckle switch signal to the combination meter assembly via CAN communication. |
|
Sends the vehicle speed signal to the combination meter assembly via CAN communication. |
|
ECM |
Sends the shift position signal to the combination meter assembly via CAN communication. |
- *1: for Vacuum brake booster
- *2: for Hydraulic brake booster
How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT
HINT:
Use these procedure to troubleshoot the seat belt warning system.
*: Use the Techstream.
PROCEDURE
1.
VEHICLE BROUGHT TO W ...
Data List / Active Test
DATA LIST / ACTIVE TEST
1. 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 p ...
Other materials:
Fail-safe Chart
FAIL-SAFE CHART
1. FAIL SAFE OPERATION
If there is a problem with any sensor signals or hydraulic brake booster
systems, the skid control ECU prohibits the power supply to the actuator
in the hydraulic brake booster and informs the ECM of VSC system failure.
The hydraulic brake b ...
Removal
REMOVAL
PROCEDURE
1. REMOVE REAR SEAT CUSHION ASSEMBLY
(a) Remove the 6 bolts and 2 rear seat cushion assemblies.
2. REMOVE NO. 4 ROOM PARTITION COVER LH
3. REMOVE NO. 4 ROOM PARTITION COVER RH
4. REMOVE NO. 3 ROOM PARTITION COVER
...
Disassembly
DISASSEMBLY
CAUTION / NOTICE / HINT
HINT:
Use the same procedure for both the LH and RH sides.
The procedure described below is for the LH side.
PROCEDURE
1. REMOVE NO. 1 HEADLIGHT BULB
(a) Turn the No. 1 headlight bulb in the direction indicated by the arrow
i ...