Immobilizer System

The immobilizer system prevents the vehicle from being used if a non Volvo original key for that vehicle is used to start the vehicle. The identity of the remote key is checked electronically when to ensure that the correct remote key is inserted in the Start control module (SCU). On cars with the keyless system it is checked by the keyless vehicle module (KVM). If the remote key is not approved, the steering column lock will not be unlocked and the engine will not start. The customer will not notice the function of the system as long as a valid remote key is used and no fault occurs.

Remote-controlled immobilization 

Applies to the English, Dutch, and Belgian market. A special version with stricter requirements applies to the Brazilian market. Applies from and incl. structure week 201020.

On certain markets there is a function for remote-controlled immobilization and mobilization. The purpose of the function is to nullify the vehicle's programmed keys in case the vehicle is stolen, for example. The vehicle can be immobilized and mobilized either using Volvo On Call service center or via diagnostic commands in VIDA (Volvo scan tool). For certain markets vehicles can only be mobilized by Volvo On Call service center.

If the vehicle is running when immobilization is requested, the vehicle is immobilized at the next start attempt. Central electronic module (CEM) can, in certain markets, request immobilization if the module detects that Phone module (PHM) does not answer to communication.

The function remote-controlled immobilization is diagnosed by Central electronic module (CEM). Immobilization and mobilization of vehicles via diagnostic commands takes place via Phone module (PHM).

Deactivation and start (only cars without the keyless locking system) 

To deactivate the immobilizer system, the remote key must be inserted in the Start control module (SCU) (3/132). When the remote key is inserted in the Start control module (SCU), the Central electronic module (CEM) (4/56) transmits the command to the Start control module (SCU) that the remote key identity must be checked. The Start control module (SCU) activates the antenna and reads off the identity code from the remote key's transponder. This code is transmitted to the Central electronic module (CEM) and compared with the codes that are programmed in the Central electronic module (CEM). If the read off code from the remote key is in the Central electronic module (CEM), the key is approved.

If the vehicle has an alcolock (option 2008-), an approved breathalyzer test must be performed in order for the handset unit to send an approved signal to the Central electronic module (CEM) to work via the Remote Receiver Module (RRX).

Central electronic module (CEM) will then activate voltage supply to the fuel pump module (PEM).

Central electronic module (CEM) will, after approval of the remote key, check the signals on the CAN-net regarding the vehicle's speed and the engine's status.

If the vehicle is at a standstill and the engine is not running, the Central electronic module (CEM) will activate voltage feed to Steering column lock module (SCL) (4/102) via an internal relay in Central electronic module (CEM), and then send a command to Steering column lock module (SCL) to unlock the steering column lock.

The vehicle cannot be started until the lock bolt in Steering column lock module (SCL) is in unlocked position. The lock bolt's position is indicated by a switch located in Steering column lock module (SCL) and is connected to Central electronic module (CEM).

If Central electronic module (CEM) should detect that voltage feed to Steering column lock module (SCL) for some reason should become high during driving, a warning message is shown in Driver information module (DIM).

When the ignition is turned on or a start attempt is made (by pressing down a pedal and pressing the start button), the communication is checked between Central electronic module (CEM) and Engine control module (ECM).

Checking is performed to ensure that the correct codes are programmed in both control modules. Engine control module (ECM) also performs a check of the identity of Brake control module (BCM) (4/16) by reading out the serial number from Brake control module (BCM).

This number is compared to a programmed number in Engine control module (ECM).

If these checks are performed correctly, then Engine control module (ECM) activates the ignition system. Engine control module (ECM) also sends a command to Central electronic module (CEM) that the fuel pump should be permitted to continue to operate. Should a problem arise or a check is not approved, then Engine control module (ECM) will order Central electronic module (CEM) to deactivate the fuel pump. Engine control module (ECM) also checks the other parameters that are covered by the function for start inhibitor. If all conditions are fulfilled, then Engine control module (ECM) activates the relay for the starter motor. The engine can then be started.

If any of the above steps should fail, the engine will not start and a message will be displayed in the driver information module (DIM).

The immobilizer system has built-in diagnostic test modes (DTM) to ensure that the engine can be restarted after unintentional stops.

Passive deactivation and start (only cars with the keyless locking system) 

To carry out a start of a keyless vehicle, a pedal must be depressed (clutch (MAN) or brake (AUT)) and the starter button pushed. When the starter button is pushed, an input on the keyless vehicle module (KVM) (4/93) is supplied with voltage, which searches for a remote key with passive function in the vehicle. The signal from the starter button also goes to the Central electronic module (CEM) (4/56), which, at the same time, transmits an encrypted request to the Keyless vehicle module (KVM). This request is responded to only if an approved passive remote key has been registered. If a remote key is found, the keyless vehicle module (KVM) checks that it is approved. If this is the case, the keyless vehicle module (KVM) transmits a response to the central electronic module (CEM) indicating that the remote key is approved.

If a passive remote control key cannot be found then the central electronic module (CEM) will instead send a request to the start control module (SCU) (3/132) to scan for a transponder. If an approved transponder is identified then the central electronic module (CEM) will approve the key.

If a start attempt is made, either non-keyless or keyless, the Central electronic module (CEM) will check the signals on the CAN-net regarding the vehicle's speed and the engine's status.

If the vehicle is at a standstill and the engine is not running, then Central electronic module (CEM) will activate voltage feed to Steering column lock module (SCL) (4/102) via an internal relay and will then send a command to Steering column lock module (SCL) to unlock the steering column lock.

The vehicle cannot be started until the lock bolt in Steering column lock module (SCL) is in its unlocked position.

The lock bolt's position is indicated by a switch located in Steering column lock module (SCL) and is connected to Central electronic module (CEM). During driving, continuous checking is performed of the Central electronic module (CEM) to make sure that the steering column lock is not activated accidentally.

If Central electronic module (CEM) should detect that voltage feed to Steering column lock module (SCL) for some reason should become high during driving, a warning message is shown in Driver information module (DIM).

When the ignition is turned on or a start attempt is made (by pressing down a pedal and pressing the start button), the communication is checked between Central electronic module (CEM) and Engine control module (ECM).

Checking is performed to ensure that the correct codes are programmed in both control modules.

Engine control module (ECM) also checks the identity of Brake control module (BCM) (4/16) by reading out the serial number from Brake control module (BCM). This number is compared to a programmed number in Engine control module (ECM).

If these checks are performed correctly, then Engine control module (ECM) activates the ignition system. Engine control module (ECM) also sends a command to Central electronic module (CEM) that the fuel pump should be permitted to continue to operate.

Should a problem arise or a check is not approved, then Engine control module (ECM) will order Central electronic module (CEM) to deactivate the fuel pump. Engine control module (ECM) also checks the other parameters that are covered by the function for start inhibitor.

If all conditions are fulfilled, then Engine control module (ECM) activates the relay for the starter motor. The engine can then be started.

If any of the above steps should fail, the engine will not start and a message will be displayed in the driver information module (DIM).

The immobilizer system has built-in diagnostic test modes (DTM) to ensure that the engine can be restarted after unintentional stops.

Activation 

System for immobilizer is activated when the ignition is turned off.

Engine start is prevented when the system is activated. Engine control module (ECM) deactivates the ignition system and prevents the relay for the starter motor to be activated. Central electronic module (CEM) will deactivate the fuel pump at the same time.

If the driver door is opened, Central electronic module (CEM) will check the signals on the CAN-net regarding the engine's status and vehicle speed. If the engine is off and the vehicle is at a standstill the Central electronic module (CEM) will activate voltage feed to Steering column lock module (SCL) and thereafter send command for the steering column lock to be locked.