Function

Function

Locking




Locking takes place when one of the lock buttons on the door handles is pressed in. A ground signal is sent from the lock button to the keyless vehicle module (KVM). The keyless vehicle module (KVM) then activated the antennas in the door handles on the side of the vehicle that the lock button was pressed. A request for a key is transmitted via the antennas. The response from the key is received by the remote keyless entry (TRX) receiver. The keyless vehicle module (KVM) checks the identity of the key against the its programmed codes. If the key is approved, the keyless vehicle module (KVM) transmits a signal to the central electronic module (CEM) to lock the vehicle. The vehicle cannot be locked from the luggage compartment/tailgate.
During a key check outside the vehicle, the internal antennas in the passenger and luggage compartment are also activated. This is to scan for any keys remaining inside the vehicle. If there are keys inside, the keyless vehicle module (KVM) will register their identities. Any signals from these keys will be ignored. This applies until the next time the vehicle is unlocked. This is to prevent remaining keys from being used to unlock or start the vehicle from outside using the starter switch. A deactivated key is reset when unlocking the vehicle, under the condition that they remain in the passenger compartment when unlocking, or if any of the locking buttons are depressed on the remote control that has been deactivated.

Note! A key which is deactivated and then somehow removed from the vehicle, cannot be used to unlock or start the vehicle. To activate the key, it must be placed inside the vehicle during an unlocking procedure.

Locks the vehicle via command from the remote control, there is no communication between the keyless vehicle module (KVM) and the key. The keyless vehicle module (KVM) then only receives a message from the remote control, checks if the key is approved and then sends a lock command to the central electronic module (CEM). In this instances locking is fully controlled by the central electronic module (CEM). However, if any keys are left inside the vehicle, they will be deactivated in the same way as above.

Unlocking




Two micro-switches are closed if a door handle is pulled out. A switch in the handle closes first followed by a switch in the quick lock.
When the contact breaker in the handle is closed, the keyless vehicle module (KVM) activates the antennas in the door handles on the front and rear doors on the side on which the handle was pulled out. A request is transmitted via the antennas to the passive key. The key transmits an encrypted response which is received by the remote keyless entry (TRX) receiver. The remote keyless entry (TRX) receiver checks that the received signal is from a Volvo key. If it is, the message is forwarded to the keyless vehicle module (KVM). The keyless vehicle module (KVM) decrypts the signal and compares it with its own codes. If these correspond, the keyless vehicle module (KVM) transmits two signals. One to the quick lock, in the door on which the handle was pulled out, to unlock and open the door. The other signal is transmitted to the central electronic module (CEM) which unlocks the other doors, depending on the system settings. The settings are:
- total unlocking
- selective unlocking.
In order for the keyless vehicle module (KVM) to activate the quick lock function, the handles must be pulled out far enough to close the switch in the lock unit.
A similar procedure to the above is carried out if the handle on the boot lid or luggage compartment lid is acted on. However, only the antenna in the rear bumper is activated to check the key. If selective unlock is set, only the boot lid/luggage compartment lid is unlocked and opened. If total unlocking is selected, the side doors will also be unlocked if the switch on the luggage compartment lid/boot lid is activated.
Passive start - Keyless vehicle module (KVM) Description and Operation
Passive key warning
Passive key warning alerts the driver that a validated key has been removed from the passenger compartment.
If a passive key has been validated and used to start the vehicle, the validation only applies until the vehicle is switched off by the start knob. If the engine is running and a door is opened, the system will scan the passenger compartment for keys as soon as all doors are closed. If the key that was used to start the vehicle is not detected, a warning message will be displayed in the driver information module (DIM) and an audible signal heard. The system will scan for keys each time a door is opened and all doors are closed again or when the driver presses the READ button. The engine will not be switched off. However, the immobilizer system activates and blocks new start attempts as soon as the starter switch is turned to position 0.

Reminder for the starter switch
So that the starter switch is not unintentionally left with the ignition on, a warning signal sounds if the driver's door is opened while the engine is not running. This prevents certain systems which could drain the car battery from remaining active.