System Overview: Signals

The tables below summarize the input and output signals to the units in the system for the immobilizer. The signal types are divided into directly connected signals, serial communication and controller area network (CAN) communication.

CENTRAL ELECTRONIC MODULE (CEM) (4/56)

Input signals	Output signals
Directly connected:	Directly connected:
Start button (IAU) (3/1). Switch at brake pedal for indicating pressed pedal (AUT). Brake light switch (3/9) and diagnostic switch brake lights (3/284). Switch at the clutch pedal which indicates when the pedal is depressed (MAN). Clutch pedal sensor (7/123).
Via serial communication (LIN):	Via serial communication (LIN):
Ignition antenna unit (IAU) (16/65) for communication with remote key. Remote Receiver Module (RRX) (4/103) for communication with remote keys and the alcolock's (option) handset unit (only vehicles without the keyless lock system).	Ignition antenna unit (IAU) (16/65) for communication with remote key. Remote Receiver Module (RRX) (4/103) for communication with remote keys and the alcolock's (option) handset unit (only vehicles without the keyless lock system).
Via CAN communication (MS-CAN):	Via CAN communication (MS-CAN):
Keyless vehicle module (KVM) (4/93) to check the identity of the remote key and approve vehicle start (only vehicles with the keyless locking system). Phone module (PHM) (16/60) (only vehicles with remote-controlled immobilization).	Driver information module (DIM) (5/1) for displaying messages. Keyless vehicle module (KVM) (4/93) to check the identity of the remote key and approve vehicle start (only vehicles with the keyless locking system). Phone module (PHM) (16/60) (only vehicles with remote-controlled immobilization).
Via CAN communication (HS-CAN):	Via CAN communication (HS-CAN):
Engine control module (ECM) (4/46) with information on engine status and status of clutch pedal switch (3/271) as well as for the immobilizer function. Brake control module (BCM) (4/16) with information about the vehicle's speed. Transmission control module (TCM) (4/28) with information about the gear selector position.	Engine control module (ECM) (4/46) for communication and checking identity.

IGNITION ANTENNA UNIT (IAU) (16/65)

Input signals	Output signals
Directly connected:	Directly connected:
Power supply from the central electronic module (CEM) (4/56).
Via serial communication (LIN):	Via serial communication (LIN):
Central electronic module (CEM) (4/56) for communication with the remote key.	Central electronic module (CEM) (4/56) for communication with the remote key.

ENGINE CONTROL MODULE (ECM) (4/46)

Input signals	Output signals
Directly connected:	Directly connected:
Start button (IAU) (3/1).	Starter motor relay for activating the starter motor.
Via Controller Area Network (CAN) communication:	Via Controller Area Network (CAN) communication:
Serial number from the Brake control module (BCM) (4/16). Communication with the central electronic module (CEM) (4/56) during start attempts.	Information about the engine status Communication with the central electronic module (CEM) (4/56) during start attempts. Communication with the brake control module (BCM) (4/16) during start attempts.

BRAKE CONTROL MODULE (BCM) (4/16)

Input signals	Output signals
Via Controller Area Network (CAN) communication:	Via Controller Area Network (CAN) communication:
Inquiry about the serial number from the engine control module (ECM) (4/46)during start attempts.	Information about vehicle speed. Serial number and P/N to the engine control module (ECM) (4/46).

TRANSMISSION CONTROL MODULE (TCM) (4/28)

Input signals	Output signals
Via Controller Area Network (CAN) communication:	Via Controller Area Network (CAN) communication:
-	Information about the position of the gear selector.

DRIVER INFORMATION MODULE (DIM) (5/1).

Input signals	Output signals
Via Controller Area Network (CAN) communication:	Via Controller Area Network (CAN) communication:
From Central electronic module (CEM) (4/56) with information about what message shall be shown in display as well as if warning signal is to sound. From the keyless vehicle module (KVM) (4/93) with information that no key was found.

PHONE MODULE (PHM) (16/60)

Input signals	Output signals
Via Controller Area Network (CAN) communication:	Via Controller Area Network (CAN) communication:
From Central electronic module (CEM) (4/56) with information about remote-controlled immobilization.	To Central electronic module (CEM) (4/56) with information about remote-controlled immobilization.