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:
Parking brake
Lever type
● Sets the parking brake
Fully set the parking brake while depressing the brake pedal.
At this time, the indicator will come on.
● Release the parking brake
Press the button
Turn the lever clockwise
Press it in completely
Pedal type
Sets the parking brake*.
...
Skid Control Buzzer Circuit (C1A4A)
DESCRIPTION
Based on dynamic radar cruise control system operation, the forward recognition
camera provides warnings to the driver by sounding the skid control buzzer.
DTC C1A4A is stored when a malfunction is detected in the skid control buzzer
circuit.
DTC No.
Detectio ...
System Voltage Circuit Short to Ground or Open (P056014)
DESCRIPTION
The battery supplies power to the ECM even when the ignition switch is off. This
power allows the ECM to store data such as DTC history, freeze frame data and fuel
trim values. If the battery voltage falls below a minimum level, the ECM data is
cleared and the ECM determines that ...
