Toyota 4Runner: System Description

SYSTEM DESCRIPTION

1. ENGINE IMMOBILISER SYSTEM DESCRIPTION

(a) The engine immobiliser system determines whether or not to enable starting of the SFI system based on a comparison of the key ID code and the vehicle pre-registered code. The engine immobiliser system compares the vehicle certification ECU pre-registered ID code with the key-embedded transponder chip ID code. If the ID codes do not match, the engine immobiliser system activates and the SFI system cannot be started. The certification ECU manages communication with the SFI system, power management control ECU, steering lock ECU and ID code box. When the ID codes of the transponder chip and certification ECU match, the certification ECU authorizes the starting of the SFI system.

2. FUNCTION OF MAIN COMPONENT

3. SYSTEM FUNCTION

(a) Using the entry function

(1) When the driver (or an occupant) gets in the vehicle and depresses the brake pedal while carrying the key, the power management control ECU recognizes that the brake pedal is depressed and sends a key certification request signal to the certification ECU. Then the certification ECU generates a request signal and sends it to the indoor electrical key oscillator. When the request signal is received, the indoor electrical key oscillator sends another request signal in order to detect whether the key is inside the vehicle. When the key receives this request signal, it sends back an ID code which includes a response code. The ID code sent from the key is sent to the certification ECU via the door control receiver. When the ID code is received, the certification ECU analyzes the code. If the certification result is normal, the certification ECU sends a key certification compatible response signal to the power management control ECU. At this time, the engine switch indicator illuminates in green. When the indicator illuminates in green and the driver presses the engine switch, the power management control ECU recognizes the engine start signal, turns the ACC relay on and turns the IG1 and IG2 relays on in that order after 0.025 seconds. At this time, the certification ECU confirms that the power source mode has changed, and sends a steering unlock command signal to the power management control ECU. After this signal is received, the power management control ECU supplies the steering lock actuator with power. Then (via the ID code box) the steering lock ECU confirms that the certification ECU is the proper ECU and drives the steering actuator motor until the steering lock is unlocked. After the steering lock is unlocked, the steering lock ECU sends an unlock completion signal to the certification ECU and power management control ECU. When this signal is received, the certification ECU sends an immobiliser unset command signal to the ID code box. Once this signal is received, the ID code box sends an immobiliser unset command signal to the SFI system after confirming that the certification ECU is the proper ECU. Then the certification ECU sends a security indicator light off signal to the telltale light assembly.

(b) Not using the entry function (when the battery is depleted, the transmitter is affected by wave noise, etc.)

(1) When the driver is sitting in the vehicle while carrying the key and the brake pedal is depressed, the power management control ECU recognizes that the stop light switch is on and sends a key confirmation request signal to the certification ECU. Upon receipt of this signal, the certification ECU activates the transponder key amplifier built into the engine switch. At this time, the engine switch outputs an wave communication signal. If the driver holds the key up to the engine switch at this time, the key receives the immobiliser wave signal and responds by sending a wave signal. When the engine switch receives the wave signal from the key, it duplicates the signal and sends an ID code to the certification ECU. Upon receipt of the ID code, the code is analyzed. If the certification passes, a key certification pass response signal is sent to the power management control ECU while simultaneously sending a sound buzzer request signal to the meter ECU. When the power management control ECU receives this signal, the ACC relay is switched on and the IG1 and IG2 relays are switched on in sequence after 0.025 seconds. At this time, the engine switch indicator illuminates in green. Then the certification ECU checks that the power source mode has been changed and sends a steering lock command signal to the power management control ECU. After receiving this signal, the power management control ECU supplies power to the steering lock actuator. Then (via the ID code box) the steering lock ECU confirms that the certification ECU is certified and drives the steering actuator motor until the steering lock is unlocked. After unlocking the steering lock, an unlock completed signal is sent to the certification ECU. Upon receipt of this signal, the certification ECU sends an unset command signal to the ID code box. Once this signal is received, the ID code box confirms that the certification ECU is certified, sends an immobiliser unset command signal to the SFI system, and then the certification ECU sends a security indicator light off signal to the telltale light assembly.