REPLACING CONTROL MODULE
When replacing the control module, the settings from the old module must be programmed into the new one for the system to work. When downloading software into the new control module, all relevant codes and ID numbers for the remote keys are also downloaded.
Scheme 683
Locking takes place when one of the lock buttons on the door handles is pressed in. A ground signal is forwarded from the lock button to the keyless vehicle module (KVM), which in turn, activates the inner antennas. A command is transmitted out to the passenger compartment that any remaining remote keys must not respond to the command. This is because the magnetic field from the external antennas can also reach inside the vehicle.
Then the keyless vehicle module (KVM) activates the antenna in the rear door handle on the side of the vehicle where the lock button was pressed in and transmits a request for a remote key. The response from the remote key contains, among other things, the remote key's ID code and is received by the remote keyless entry (TRX). The keyless vehicle module (KVM) checks the identity of the remote key against the programmed codes. If the remote 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/boot lid.
After the vehicle has been locked, the inner antennas in the passenger compartment and luggage compartment reactivate to find out if there are any remote keys left in the vehicle. If there are, the Keyless vehicle module (KVM) registers the identity of the remaining remote keys and will not use signals from them. This applies until the vehicle is unlocked the next time.
This is done so that the remaining remote keys cannot be used to unlock the vehicle "passively" or start the vehicle from the outside. The function of the deactivated remote keys is reset when the vehicle is unlocked by another authorized remote key or if the unlocking button is pressed on one of the deactivated remote keys. Resetting also occurs when the remote key is inserted into the Start control module (SCU).
If the vehicle is locked by one of the lock buttons on the remote key being pressed, there is no communication between the keyless vehicle module (KVM) and the remote key. The keyless vehicle module (KVM) then only receives a message from the remote key checks if it 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 remote keys are left inside the vehicle, they will be deactivated in the same way as above.
Scheme 684
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 handle on the rear doors on the side on which the handle was pulled out. A request is transmitted via the antenna to the passive remote key. The remote 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 remote key. If it is, the message is forwarded to the keyless vehicle module (KVM). The keyless vehicle module (KVM) decrypts the signal and compares the received code from the remote key with its own programmed codes. If these correspond, the keyless vehicle module (KVM) transmits two signals. One signal is transmitted 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 remote 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.