Toyota Tacoma manuals

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).

  • Front occupant classification sensor LH
  • Front occupant classification sensor RH
  • Rear occupant classification sensor LH
  • Rear occupant classification sensor RH

Informs the occupant detection ECU of the front passenger seat condition (occupied or unoccupied).

Combination meter assembly

  • The combination meter assembly illuminates, blinks or turns off the seat belt warning light.
  • The combination meter assembly sounds the seat belt warning buzzer.

Occupant detection ECU

Sends the front passenger seat belt buckle switch signal and occupant detection signal to the airbag sensor assembly.

Airbag sensor assembly

  • Sends the driver seat belt buckle switch signal to the main body ECU via CAN communication.
  • Sends the front passenger seat belt buckle switch signal to the combination meter assembly via CAN communication.

Main body ECU

Sends the driver seat belt buckle switch signal to the combination meter assembly via CAN communication.

  • Brake actuator assembly (Skid control ECU)*1
  • Brake booster with master cylinder assembly (Skid control ECU)*2

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:

Replacement
REPLACEMENT PROCEDURE 1. REPLACE AUTOMATIC TRANSMISSION FLUID (a) Lift the vehicle. [*1] NOTICE: Set the vehicle on a lift so that the vehicle is kept level when it is lifted up (make sure that the tilt angle from the front to rear of the vehicle is within +/-1°). (b) Remove th ...

Dtc Check / Clear
DTC CHECK / CLEAR 1. DTC CHECK 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 / Trouble Codes. (e) Check for DTCs. 2. DTC CLEAR USING TECHSTREAM (a) Conn ...

Malfunction of ID-BOX Recognition (B278D)
DESCRIPTION When the certification ECU (smart key ECU assembly) detects an input signal indicating that the vehicle is equipped with an ID code box even though the ID code box is not registered, the certification ECU (smart key ECU assembly) stores this DTC. DTC Code DTC ...

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