Engine Immobilizer System (w/ Smart Key System)

THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER SYSTEM (w/ Smart Key System): SYSTEM DIAGRAM





Function of Main Components










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 (smart key ECU assembly) pre-registered ID code with the electrical key transmitter-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 (smart key ECU assembly) manages communication with the SFI system, power source control ECU, steering actuator assembly (steering lock ECU) and ID code box (immobiliser code ECU). When the ID codes of the transponder chip and certification ECU (smart key ECU assembly) match, the certification ECU (smart key ECU assembly) authorizes the starting of the SFI system.

2. SYSTEM FUNCTION

* *1: for Automatic Transaxle

* *2: for Manual Transaxle

(a) Using the entry function

(1) When the driver (or an occupant) gets in the vehicle and depresses the brake pedal*1 or clutch pedal*2 while carrying the electrical key transmitter, the power source control ECU recognizes that the brake pedal*1 or clutch pedal*2 is depressed and sends an electrical key transmitter certification request signal to the certification ECU (smart key ECU assembly). Then the certification ECU (smart key ECU assembly) 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 electrical key transmitter is inside the vehicle. When the electrical key transmitter receives this request signal, it sends back an ID code which includes a response code. The ID code sent from the electrical key transmitter is sent to the certification ECU (smart key ECU assembly) via the door control receiver. When the ID code is received, the certification ECU (smart key ECU assembly) analyzes the code. If the certification result is normal, the certification ECU (smart key ECU assembly) sends an electrical key transmitter certification compatible response signal to the power source 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 source 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 (smart key ECU assembly) confirms that the power source mode has changed and sends a steering unlock command signal to the power source control ECU. After this signal is received, the power source control ECU supplies the steering lock actuator assembly (steering lock ECU) with power. Then (via the ID code box [immobiliser code ECU]) the steering actuator assembly (steering lock ECU) confirms that the certification ECU (smart key ECU assembly) is the proper ECU and drives the steering actuator motor until the steering lock is unlocked. After the steering lock is unlocked, the steering actuator assembly (steering lock ECU) sends an unlock completion signal to the certification ECU (smart key ECU assembly) and power source control ECU. When this signal is received, the certification ECU (smart key ECU assembly) sends an immobiliser unset command signal to the ID code box (immobiliser code ECU). Once this signal is received, the ID code box (immobiliser code ECU) sends an immobiliser unset command signal to the SFI system after confirming that the certification ECU (smart key ECU assembly) is the proper ECU. Then the certification ECU (smart key ECU assembly) sends a security indicator light "off "signal to the clock assembly (security indicator light).

(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 electrical key transmitter and the brake pedal*1 or clutch pedal*2 is depressed, the power source control ECU recognizes that the stop light switch*1 or clutch start switch*2 is on and sends an electrical key transmitter confirmation request signal to the certification ECU (smart key ECU assembly). Upon receipt of this signal, the certification ECU (smart key ECU assembly) activates the transponder key amplifier built into the engine switch. At this time, the engine switch outputs a wave communication signal. If the driver holds the electrical key transmitter up to the engine switch at this time, the electrical key transmitter receives the immobiliser wave signal and responds by sending a wave signal. When the engine switch receives the wave signal from the electrical key transmitter, it duplicates the signal and sends an ID code to the certification ECU (smart key ECU assembly). Upon receipt of the ID code, the code is analyzed. If the certification passes, an electrical key transmitter certification pass response signal is sent to the power source control ECU while simultaneously sending a sound buzzer request signal to the combination meter assembly. When the power source 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 (smart key ECU assembly) checks that the power source mode has been changed and sends a steering lock command signal to the power source control ECU. After receiving this signal, the power source control ECU supplies power to the steering lock actuator assembly (steering lock ECU). Then (via the ID code box [immobiliser code ECU]) the steering lock actuator assembly (steering lock ECU) confirms that the certification ECU (smart key ECU assembly) 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 (smart key ECU assembly). Upon receipt of this signal, the certification ECU (smart key ECU assembly) sends an unset command signal to the ID code box (immobiliser code ECU). Once this signal is received, the ID code box (immobiliser code ECU) confirms that the certification ECU (smart key ECU assembly) is certified, sends an immobiliser unset command signal to the SFI system, and then the certification ECU (smart key ECU assembly) sends a security indicator light "off" signal to the clock assembly (security indicator light).

3. START FUNCTION PROBLEM SYMPTOMS









* *1: Refer to Problem Symptoms Table for Smart Key System (for Start Function) Problem Symptoms Table.

* *2: Refer to Problem Symptoms Table for Steering Lock System Problem Symptoms Table.