The electronic key will not lock and unlock the doors. When held up to the start ignition button the car cranks properly. However, once it’s cranked the “cannot detect key” prompt comes on. I have replaced the battery in the key.
RESPONSE
Cannot Detect Key System Description
1. ENGINE IMMOBILISER SYSTEM DESCRIPTION
(a) The engine immobiliser system determines whether or not to disable starting of the SFI system based on a comparison of the key‘s ID codes and the vehicle’s pre-registered code. The engine immobiliser system compares the vehicle certification ECU’s pre-registered ID code with the key-embedded transponder chip’s 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, main body ECU (driver side junction block), 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
Component | Outline |
|---|---|
Transponder key coil/amplifier (built into engine switch) | Receives key ID code, amplifies ID code and outputs it to certification ECU |
Indoor electrical key oscillator | Transmits key detection signals within detection area in vehicle interior upon receiving transmission request signal from certification ECU. Certification ECU request signal is activated when key is brought into vehicle interior and engine switch is pushed. |
Door control receiver | Receives ID code from key in actuation area and transmits it to certification ECU |
Security indicator light | Illuminates or starts blinking. Illumination is controlled by front multiplex network door ECU. |
3. SYSTEM FUNCTION
(a) Using entry function
(1) When the driver (or passenger) is sitting in the vehicle while carrying the key, and the brake pedal is depressed while the engine switch is pressed, the main body ECU (driver side junction block) recognizes that the engine start operation has occurred and sends a certification request signal to the certification ECU. Upon receipt of the certification request signal, the certification ECU sends a request signal to the indoor electrical key oscillator. Upon receipt of the request signal, the indoor electrical key oscillator sends a request signal to detect if the key is inside the vehicle. When the key receives this request signal, it answers by sending an ID code containing a response code through the glass antenna to the door control receiver. Upon receipt of the ID code, the certification ECU analyzes the code. If the interior certification passes, then the main body ECU (driver side junction block) sends a certification pass response signal. When the main body ECU (driver side junction block) 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 main body ECU (driver side junction block). After receiving this signal, the main body ECU (driver side junction block) 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’s 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 sends a security indicator light off signal to the front multiplex network door ECU LH and RH.
(b) Not using the entry function (when battery is depleted, 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 main body ECU (driver side junction block) 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 drives the motor of the engine switch’s built-in immobiliser amplifier. At this time the engine switch sends an RF wave communication signal to the immobiliser. If the driver holds the key up to the engine switch at this time, the engine switch receives the immobiliser RF wave signal and responds by sending a radio wave signal. When the engine switch receives the radio 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 main body ECU (driver side junction block) while simultaneously sending a sound buzzer request signal to the meter ECU. When the main body ECU (driver side junction block) 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 main body ECU (driver side junction block). After receiving this signal, the main body ECU (driver side junction block) 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’s 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 sends a security indicator light off signal to the front multiplex network door ECU LH and RH.