System Overview: Signals

The table below summarizes the input signals to and output signals from the central electronic module (CEM). The signal types are divided into directly connected signals, serial communication and controller area network (CAN) communication.

Input signals	Output signals
Directly connected:	Directly connected:
Horn switch Trunk lid, unlocking Deadlocking switch Stop lamp switch Fuel tank filler cap, unlocking Private locking switch Control signal for doors/hatches (x6) Blower fan, re-supply Twilight sensor Sun sensor Fuel level sensor The DC/AC converter fuel tank (only B4184S8) Fuel level sensor (AWD) Seat belt buckle sensor, rear (x3) Supplemental Restraint System Module (SRS), collision output signal Hazard warning signal flasher switch Vicinity signal, ignition key Dip switch Sun roof speed signal Washer fluid level sensor Fuel pump, re-supply Brake fluid level switch Reverse gear sensor Parking brake switch Clutch pedal sensor (5 cylinder engines with manual transmissions) Accelerator pedal (AP) position sensor Battery temperature sensor (replaced by software starting from structure week 200605) Outside temperature gauge Light switch module (LSM) Secondary battery (2010-, only on vehicles with the function automatic start/stop of engine).	Parking lamps License plate lighting Brake light Dipped beam Passenger compartment lighting Fog tail lamps Hazard warning signal flasher indicator lamp Shift lock High level stop lamp PAD-warning light (passenger airbag disconnected warning lamp) PAE-warning light (warning light activated airbag passenger) (2008-) Seat belt reminder Fuel tank filler cap, unlocking Turn signal lamps Malfunction indicator lamp (MIL). Alarm LED Mass movement sensor module (MMS), or ultrasonic sensor module (IMS), voltage supply Steering Column Lock Module (SCL), wake-up (does not apply to USA/CDN market for 2009-). Engine control module (ECM), stimulation Dimmer switch, instrument lighting Trunk lid, unlocking Receiver, power supply Sun roof, closing signal Frequency signal, electrical additional heater Frequency signal blower fan Indicator lamp, deadlock Passenger seat sensor, supply voltage Fuel pump, relay Infotainment relay Rear windshield washer, relay High beam, relay Front windshield washer, relay Rear demist, relay Extended power supply, relay Passenger compartment lighting (power supply) Reversing lamp, relay Ignition switch interlock, relay Front fog lamps, relay Headlamp washer, relay Horn, relay Tailgate wiper, relay Light switch module (LSM) LEDs in doors for lock indication LEDs in switch roof movement (only C70, 2008-) Humidity sensor, voltage supply (option, only ECC 2008-) Alcolock, voltage supply (option 2009-) Daytime running lights, relay (from structure week 201044, option)
Via serial communication:	Via serial communication:
Gas discharge lamp module (GDL) (2 pcs.) (optional equipment) (S40/V50 -200719, C30/C70 -200945) Remote control receiver Rain sensor module (RSM) (optional extra) Steering Column Lock Module (SCL) (does not apply to USA/CDN market for 2009-). Siren control module (SCM) (optional extra) Start control module (SCU) Wiper motor module (WMM) Sun roof module (SRM) Humidity sensor (option, only ECC 2008-) Battery monitoring sensor (7/240), with signals about the battery's (main battery) status. Only on vehicles with the function brake energy regeneration 201020- (for D4164T the battery monitoring sensor is connected to Engine control module (ECM)).	Gas discharge lamp module (GDL) (2 pcs.) (optional equipment) (S40/V50 -200719, C30/C70 -200945) Remote control receiver Rain sensor module (RSM) (optional extra) Steering Column Lock Module (SCL) (does not apply to USA/CDN market for 2009-). Siren control module (SCM) (optional extra) Start control module (SCU) Wiper motor module (WMM) Sun roof module (SRM) Humidity sensor (option, only ECC 2008-) Battery monitoring sensor (7/240), with signals such as start key position and diagnostic commands. Only on vehicles with the function brake energy regeneration 201020- (for D4164T the battery monitoring sensor is connected to Engine control module (ECM)).
Via Controller Area Network (CAN) communication:	Via Controller Area Network (CAN) communication:
Accessory electronic module (AEM) (optional extra) Brake control module (BCM) Climate control module (CCM) Combustion preheater module (CPM) (optional extra) Driver door module (DDM) Driver information module (DIM) Engine control module (ECM) Electrical power steering module (EPS) Infotainment control module (ICM) Passenger door module (PCM) Phone module (PHM) (optional extra) Power seat module (PSM) (optional extra) Supplemental restraint system module (SRS) Steering wheel module (SWM) Transmission control module (TCM) (optional extra) Trailer module (TRM) (optional extra). Convertible Roof Module Headlamp Control Module (HCM) (S40/V50 200720-, C30/C70 200946-)	Accessory electronic module (AEM) (optional extra) Brake control module (BCM) Climate control module (CCM) Combustion preheater module (CPM) (optional extra) Driver door module (DDM) Driver information module (DIM) Engine control module (ECM) Electrical power steering module (EPS) Infotainment control module (ICM) Passenger door module (PCM) Phone module (PHM) (optional extra) Power seat module (PSM) (optional extra) Supplemental restraint system module (SRS) Steering wheel module (SWM) Transmission control module (TCM) (optional extra) Trailer module (TRM) (optional extra). Convertible Roof Module (CRM) Power seat module, left (PSL) Power seat module, right (PSR) Headlamp Control Module (HCM) (S40/V50 200720-, C30/C70 200946-)