Design

Design

Control module




The keyless vehicle module (KVM) is located behind the right-hand wheel arch in the cargo compartment. The control module controls and monitors the keyless entry system. The keyless vehicle module (KVM) uses the external and internal antennas to communicate with the remote key and to control the quick locks in the doors.
The keyless vehicle module (KVM) activates the internal or external antennas depending on the input signals and commands it receives. The control module also checks the identity of the remote key.
The keyless vehicle module (KVM) is part of the immobilizer system. It works with the central electronic module (CEM) to check remote key identities. For further information, see Design and Function, Immobilizer/Start inhibition.
The keyless vehicle module (KVM) must be programmed with various codes before it can function in the system. For further information, see: Downloading software and replacing the control module Testing and Inspection
The two control modules communicate over the LS-CAN.
The keyless vehicle module (KVM) contains 4 power stages. The control module uses these relays to select the antennas to be activated. See the table below:





Keyless vehicle module (KVM) is 30-supplied via the Central electronic module (CEM) and grounded in the body. The Keyless vehicle module (KVM) is always supplied with power as long as the vehicle is powered.

Note! During locking, the keyless vehicle module (KVM) only checks the quick lock motors in the doors. The other lock motors and the other functions in the central locking system are checked by the central electronic module (CEM).

Internal antennas





There is a total of three internal antennas. The internal antennas are under the carpet:
- under the center panel
- between the center console and the rear seat
- in the cargo compartment.
The antennas allow the keyless vehicle module (KVM) to communicate with the passive remote key. The keyless vehicle module (KVM) activates the internal antennas in the event of any of the following:
- a signal is received from the contact breaker when the starter button is pressed in
- a signal is received indicating that the brake pedal (automatic transmissions) or clutch pedal (manual transmissions) is pressed
- a lock command is received from the remote key
- a lock button at one of the external door handles is pressed in
- the first switch in one of the external door handles is closed
- a request to check the remote key from the central electronic module (CEM).
The antennas are also activated when the vehicle is locked. This to deactivate any remote keys which are still in the vehicle. This is so that the vehicle cannot be passively started/unlocked by any remote keys still in the passenger compartment. The remote keys are reactivated when the vehicle is unlocked or when the button for unlocking is pressed on a deactivated remote key.
The keyless vehicle module (KVM) checks the internal antennas every operating cycle if the vehicle speed is in excess of 20 km/h (12 mph).
The antennas are powered by the keyless vehicle module (KVM).

External antennas




The outer antennas are located in the door handles on the rear doors and in the luggage compartment.
The antennas make it possible for the Keyless vehicle module (KVM) to communicate using a remote key outside the vehicle.
The keyless vehicle module (KVM) activates one or some of the antennas when the vehicle is locked
- the system receives a wake up signal from one of the unlocking switches in the door handles (unlocking)
- the system receives a wake-up signal from the switch on the tailgate (unlocking)
- one of the outer lock buttons is pressed in (locking)
- an unlocking command is transmitted from the Central electronic module (CEM).
The output of the antennas is adjusted during installation. This is so that there must be a valid remote key within a radius of approximately 1.5 meters from an active antenna for the system to function correctly.
The keyless vehicle module (KVM) checks the external antennas every operating cycle if the vehicle speed is in excess of 20 km/h (12 mph).
The antennas are powered by the keyless vehicle module (KVM).

Switches affected by the external door handles




Two inner contact breakers are in each handle in the outer door handles. There is also a lock button in each handle. One of the contact breakers is connected to the handle. It is acted on by a linkage system if the handle is pulled out. The other switch is acted on if the lock button is pressed in. There is also a control arm between the door handle and the quick lock. The control arm acts on a third switch inside the quick lock if the handle is pulled out fully.
The first contact breaker is closed when the handle is pulled out by 2 - 4mm. When a contact breaker is closed, an input on the keyless vehicle module (KVM) is grounded. The keyless vehicle module (KVM) wakes and activates the external antennas to scans for a valid remote key. This switch is closed for as long as the handles is pulled out.
Just before the handle is pulled out to its limit position, the switch in the quick lock is closed by the control arm from the door handle. When the switch closes, one of the inputs in the keyless vehicle module (KVM) is grounded.
This mechanical affect on the switch in the quick lock is one of the conditions for the keyless vehicle module (KVM) to activate the quick lock.
The switch connected to the lock button is closed when the lock button is pressed in. The switch instructs the keyless vehicle module (KVM) that the vehicle should be locked.

Start control module (SCU)





The start control module (SCU) is in the dashboard beside the steering wheel. Start control module (SCU) contains:
- a module for the remote key
- a motor for drawing in and ejecting the remote key
- a starter button.
The control module also contains 3 contact breakers that are mounted on top of the spring where the remote key is inserted. The contact breakers are activated on different occasions via a sledge when the remote key is inserted in the spring:
1. Switch key-inserted: activates the motor for drawing in the remote key in the Start control module (SCU).
2. Switch for locked remote key: informs the Central electronic module (CEM) that the remote key is in its locked position.
3. Switch for ejection: activates the motor for ejecting the remote key when the remote key is pushed in after it being in its locked position. In order for the remote key to be ejected, the engine must not be running, the vehicle must not be moving (speed must be 0) and for vehicles with automatic transmission, the gear selector lever must be in position P.
The Start control module (SCU) has an internal antenna that can be activated on command from the Central electronic module (CEM). The antenna is used for checking the key identity when the remote key is inserted into the compartment on the Start control module (SCU). The antenna ring is activated by the central electronic module (CEM) when the signal from the key-in contact breaker has been received
The starter button has two contact breakers.
One is directly connected to the central electronic module (CEM), the keyless vehicle module (KVM) and the engine control module (ECM).
The other is managed internally in the Start control module (SCU) which transmits the contact breaker's status to the Central electronic module (CEM) via serial communication (LIN).
Both contact breakers must be closed when the starter button is depressed. It is sufficient for one contact breaker to close for the steering wheel lock to be unlocked and the vehicle to be started. However, both contact breakers must be closed for the steering wheel lock to be unlocked when switching off the engine. This is for safety.
The remote key does not need to be in the compartment on the start control module (SCU) if there is a keyless vehicle module (KVM) in the vehicle. The identity of the remote key is then checked via the antennas in the passenger compartment instead. These antennas are connected to the keyless vehicle module (KVM) when the starter button is pushed.
The steering column lock module (SCL) is powered by the central electronic module (CEM) and grounded in the body.

Contact breaker at clutch pedal/stop lamp switch




The brake or clutch pedal must be depressed for the vehicle to start.
The clutch pedal contact breaker is only installed on vehicles with a manual gearbox and is installed with the clutch pedal.
The contact breaker is in its open position but closes when the clutch pedal is depressed more than 90% of its stroke. The Engine control module (ECM) and Central electronic module (CEM) check that the contact breaker is closed when a so-called passive start is initiated.
If the vehicle has an automatic transmission, the signal from the stop lamp switch is transmitted to the Engine control module (ECM) and Central electronic module (CEM).
The stop lamp switch is installed together with the brake pedal. The contact breaker is in its open position but closes when the brake pedal is depressed.

Lock unit with quick lock functionality




The lock unit is installed in the relevant door's rear end. The lock unit has a quick lock function which is used to reduce the reaction time of the system. The lock unit has an integrated switch which is closed when the outer door handles are pulled out to their limit positions. The switch is mechanically connected to the exterior door handle by a control arm. This allows the keyless vehicle module (KVM) to activate the quick lock motors and open the door on which the handles was pulled out. The quick lock motor is activated after a remote key has been validated by the keyless vehicle module (KVM). The quick lock is mechanically connected to the catch in the ordinary lock mechanism. On activation, the quick lock turns the catch so that it releases the striker plate in the body. This means that when the handle is pulled out on a door, the door opens as soon as the keyless vehicle module (KVM) has validated the remote key. This reduces the reaction time of the system considerably.
The key unit is powered by the keyless vehicle module (KVM).

Remote Keyless Entry (RKE)




Remote Keyless Entry (RKE) is installed on top of the headlining directly above the rear seat.
The receiver receives the signal, which comes from the remote key and forwards it to the Keyless vehicle module (KVM).
The remote keyless entry (RKE) receiver has a logic which enables it to check that a correct message is received. All communication is decrypted in the keyless vehicle module (KVM). The receiver's signal cable is directly connected to the keyless vehicle module (KVM).

The remote keyless entry (RKE) receiver has two different modes:
- normal mode
- passive mode.
In normal mode, the receiver waits for a signal from the remote key when a button is pressed.
If the keyless vehicle module (KVM) receives an indication from the door handle that someone is trying to open the vehicle using keyless entry, the keyless vehicle module (KVM) transmits a signal to the receiver to switch to passive mode for a short period of time. After this time, the receiver reverts to normal mode. The difference between these two modes is the way in which the receiver communicates with the remote key.
When a remote key has been approved and used to start the vehicle, the Central electronic module (CEM) ignores all messages from the remote keyless entry (RKE) as long as the engine is running. This prevents the status of the system from changing if a button on another remote key is unintentionally pressed in.
The remote keyless entry (RKE) receiver is 30-supply powered via the central electronic module (CEM) and grounded in the body.

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.

Note! In certain cases malfunctions may occur in the system when communication between the keyless vehicle module (KVM) and the remote key is interrupted for different reasons. These malfunctions are not due to any electrical faults and do not generate any diagnostic trouble codes (DTCs).

1. 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.
2. 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.
3. 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.