Toyota 4Runner: System Description

Toyota 4Runner Service Manual / Vehicle Interior / Door Lock / Wireless Door Lock Control System(w/ Smart Key System) / System Description

SYSTEM DESCRIPTION

1. WIRELESS DOOR LOCK CONTROL SYSTEM DESCRIPTION

(a) This system locks/unlocks the doors remotely. The wireless door lock control system has the following features:

The certification ECU performs the code identification process and the main body ECU controls the door locks. A serial data link is provided for communication between the certification ECU and main body ECU.
A key-integrated type transmitter is used and it contains the following 3 switches: the lock switch, unlock switch and panic switch.
An LED is mounted on the transmitter to show if the battery is depleted.

2. FUNCTION OF MAIN COMPONENTS

Component	Function
Door control transmitter	Contains the lock, unlock and panic switches. Transmits weak electric waves (recognition codes and function codes) to the door control receiver. Illuminates the indicator light (LED) during transmission.
Door control receiver	Receives weak electric waves (recognition codes and function codes) from the door control transmitter via the electrical key antenna and changes the waves to code data.
Front door courtesy light switch Rear door courtesy light switch Back door courtesy light switch	Turns on when the door is opened and off when the door is closed. Outputs the door status (open or closed) to the main body ECU.
Door lock position switch	Transmits the door lock positions of each door to the main body ECU.
Wireless door lock buzzer	Sounds when the door ajar warning function is operating.
Certification ECU	Matches the code data with the registered code and outputs the code data to the main body ECU.

3. SYSTEM FUNCTION

(a) The wireless door lock control system has the following functions:

Function	Outline
All door lock function	Pressing the lock switch locks all the doors.
All door unlock (Unlock 2 operation)	Pressing the unlock switch twice within 3 seconds unlocks all the doors after the driver door is unlocked.
Chattering prevention function	If a switch is pressed, the corresponding switch operation is performed once. If a switch is held down, the corresponding switch operation occurs only once and does not repeatedly activate. When pressing a switch at 1 second intervals, the corresponding operation activates once for every press of the switch.
Answer-back function	When the doors are locked by wireless operation, the hazard warning lights flash once and the wireless door lock buzzer sounds once. When the doors are unlocked by wireless operation, the hazard warning lights flash twice and the wireless door lock buzzer sounds twice.
Automatic lock function	If no doors are opened within 60 seconds after they are unlocked by the door control transmitter, all the doors lock again automatically.
Illuminated entry function	When the map light door switch is on and all the doors are locked, pressing the unlock switch causes the interior light illumination to turn on and all the doors to unlock simultaneously. If the doors have not been opened, the interior light turns off after approximately 15 seconds.
Door ajar warning function	If any door is open or ajar, pressing the lock switch causes the wireless door lock buzzer to sound for approximately 5 seconds.
Panic alarm function	Pressing the panic switch of the transmitter for more than approximately 0.8 seconds causes the following alarms to activate: Sounds the horn and security horn. Flashes the headlights, taillights and hazard warning lights. Illuminates the interior lights (when the map light door switch is on). While the panic alarm is operating, pressing any switch of the transmitter cancels the alarm operation.

Precaution

PRECAUTION 1. PRECAUTIONS FOR EACH FUNCTION (a) Precautions for the key: The key is a precision instrument. Be sure to observe the following: (1) Do not drop or strike the key. (2 ...

System Diagram

SYSTEM DIAGRAM Communication Table Sender Receiver Signal Line Certification ECU Main body ECU Door unl ...

Other materials about Toyota 4Runner:

Removal
REMOVAL PROCEDURE 1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL CAUTION: Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system. NOTICE: When disconnecting the cable, some systems ne ...

Rear Door Courtesy Switch
Components COMPONENTS ILLUSTRATION Inspection INSPECTION PROCEDURE 1. INSPECT REAR DOOR COURTESY LIGHT SWITCH ASSEMBLY (a) Measure the resistance according to the value(s) in the table below. Standard Resistance: ...