Remote Key
The remote key has a different appearance depending on which equipment the vehicle has. The inner design also differs between the two models depending on whether it has functions for keyless entry or not. The remote key also contains a key blade. The key blade is normally retracted inside the remote key. The blade is used as a standby option to open the vehicle should there be a fault in the system.
The buttons on the remote key are:
- Lock - to lock the vehicle
- Unlock - to unlock the vehicle
- A button to unlock the luggage compartment lid
- A button to activate the vehicle lighting for 30 seconds
- A button to manually trigger the alarm if an alarm is installed.
- Button for information about the vehicle's status. The button is only found on vehicle's with the keyless system and heartbeat sensor installed.
Internally, the remote key consists of four sections:
- Transponder
- Circuit for remote key/keyless functionality
- Circuit for keyless functionality.
- One part with transmitter and receiver.
The transponder is used to identify the remote key for the immobilizer system when the remote key is inserted in the compartment on the start control module (SCU). The transponder contains a unique code. The central electronic module (CEM) must be programmed with the transponder code before the vehicle can be started.
The circuit for remote key is used to lock and unlock the central locking and to activate the above functions. The circuits in the remote key which control the remote key functionality are coded. These codes must be programmed into the keyless vehicle module (KVM) for communication to work.
The circuit for keyless functionality is used for:
- Unlocking
- Locking
- Passive starting
The circuits in the remote key which control the function for the keyless entry system are coded. The keyless vehicle module (KVM) must learn these codes for communication to function.
The remote key is driven by two internal button batteries.
The batteries are used each time the remote key communicates with the system via the remote key function or the keyless entry function. The batteries are not used when communication occurs via the remote key's transponder when the remote key is inserted in the Start control module (SCU).
The battery must be replaced regularly depending on how often the remote key is used. The remote key contains an internal voltmeter that reads the voltage of the internal battery. If the battery's voltage is too low, information about this is transmitted in the messages sent to the Remote Keyless Entry (RKE). The Keyless vehicle module (KVM) receives this information and transmits a message via the CAN network to the Driver information module (DIM), which shows a message that the voltage is too low. Another indication that the battery is deteriorating is that the range of the remote key starts to reduce.
- If the remote key is held in the hand that is used to press the starter button, remote key identification can fail. This results in a message being shown in the driver information module (DIM). The vehicle will not start either. However, the vehicle will start on another start attempt. The fault does not generate any diagnostic trouble codes (DTCs). The fault is rare.
- If a button on the remote key is pressed when remote key identification is carried out, reading off will fail. This means that the remote key cannot transmit and receive data at the same time (when a button is pressed on the remote key, the remote key is busy sending "normal" remote key commands). This fault may occur if the remote key is in a pocket or bag and a button has been pressed by mistake.
- Due to increased ambient radiation, for example, from TV/radio transmitters and mobile phones and meters with remote reading, the signal from the remote key can, in some cases, be interrupted. In many cases this occurs in certain locations, where different outside signals make transmission and reception conditions unfavorable. This affects not only keyless vehicle systems but all types of wireless communication.